Yet as Stiller plays him he’s both repellent and compelling, a wayward, untethered soul who’s nonetheless so close to the shore that our impulse is to reach out and pull him in, not push him further away. That unsettling tension between wanting to flee and wanting to help — or at least comprehend — is the very center of “Greenberg,” Baumbach’s fifth movie and, possibly, his most open-hearted and raw. Baumbach kicked off his career with the clever, modern-feeling comedies of manners “Kicking and Screaming” and “Mr. Jealousy”; his next picture, the semi-autobiographical “The Squid and the Whale” was more self-conscious and a little too preening, with its “Don’t worry too much about us suffering middle-class intellectuals, we’ll be OK” undertones, although it was easy enough to feel some sympathy for the movie’s younger characters, kids caught in the current of their parents’ bitterness. But the 2007 “Margot at the Wedding” gave us no one to feel sorry for and too many people to revile: Baumbach’s portrait of a family of sad, confused little creatures suffering away in their costly-but-comfy coastal New England summer home hit a new low of cluelessness.

In a rough sense, “Greenberg” is of a piece with those two movies: Baumbach is fascinated by the cruelty that’s inflicted by people who are suffering themselves. And he’s sensitive to people in pain. As much as I disliked “Margot at the Wedding,” I can’t forget the scene in which Nicole Kidman’s character makes cruel, thoughtless comments about her preadolescent son’s changing body, and then waves away the damage she’s done by saying, “It’s OK, though.”

The difference, maybe, is that Roger Greenberg as he’s written and played isn’t a specimen or an experiment — he has the everyman believability of a person you might have known once, or probably did know. And his story is framed less by the confines of his own neurosis than by his tentative but growing connection to another character, Florence Marr (Greta Gerwig, who’s previously appeared in mumblecore features like “LOL” and “Hannah Takes the Stairs”), the young woman who works as Roger’s brother’s assistant. Her boss — he’s played by Chris Messina — and his family are on vacation in Viet Nam. Florence is in charge of looking after the house and the dog, although Roger assures her he can manage all that by himself. And essentially, he can. But for one reason or another, he keeps calling Florence. She’s at first puzzled by him, and then intrigued. Then she decides she might actually like him, even though he initially paws at her with a sexual fervor that stems less from hunger than from some internal sense of duty. When Florence, over the phone, tells her best friend about the episode, we can hear the woman’s amused assessment ringing out like the punchline to a bad joke: “A mental patient just went down on you!”

Florence is almost as physically awkward as Roger is emotionally: She has a tall, beautiful figure, but she doesn’t seem to know what kinds of clothes to hang on it. (In one scene, she lounges at home in a pair of tights and a stretchy, too-small top, breezily unselfconscious about how odd this getup looks.) And she comes off, at first, as one of those spacy young women who float through life with seeming innocence, when in reality they’re extremely canny about searching out the kinds of guys who will go overboard to take care of them.

Florence may be a little spacy, but she’s not manipulative; she’s sensitive, but not necessarily fragile. As Gerwig plays her, in this marvelously unstudied and touching performance, her gaze is both drifty and direct. At times she appears to be a woman who can barely take care of herself. When she goes home with a guy she’s just met at a party, she stammers, “I just got out of a long relationship,” to which he replies, with a voice that carries more than a hint of a smirk, “This isn’t a relationship.”

Florence gives in to the loser, partly because she simply wants to; still, an air of self-determination hangs about her shoulders like a mantle. Her powers of self-preservation are wrapped up in her essential kindness. She won’t be a doormat, but there’s something in Roger Greenberg that she refuses to turn away from. As she says to her best friend, again over the phone, “You can tell that a lot of normal stuff is really hard for him,” and that about covers it.

Baumbach wrote the screenplay for “Greenberg,” adapting it from a story he wrote with Jennifer Jason Leigh (his partner in real life), and the characters seem carefully calibrated to just drive us crazy enough. When I wrote briefly about the picture last month, from the Berlin Film Festival, I said that at first I couldn’t decide whether the characters were driving me nuts or if they were affecting me deeply. That was on the first viewing; the second time, Roger and Florence drove me even crazier and affected me more. Roger may be odd, but more often than not, he’s onto something. In the old days, he used to be a member of a semi-successful band; it was he who nixed the group’s record deal, and the other members still resent him for it, although one of his former bandmates, Ivan (played, wonderfully, by Rhys Ifans), works valiantly to keep his and Roger’s friendship alive. At one point Ivan drags Roger to a party where he’s wholly out of place. A native Los Angeleno who’s spent years in New York, Roger has no idea where he belongs, and he dresses the part: One of his favorite outfits is a puffer vest and sweater, a getup that’s as out of place in the toaster-oven light of Los Angeles as he is.

But as Roger surveys the party, a collection of listless semi-grownups draped on couches having meaningless conversations and little kids running around in devil suits, he observes out loud, “All the men out here dress like children and the children dress like superheroes.”

And he’s not wrong. Later, as he presents Florence with a mix-CD he’s made for her (it includes music by Karen Dalton, a ’60s folk singer who was a favorite of Bob Dylan’s but who suffered through homelessness and drug addiction before her death in 1993), she looks at him and says plainly, “You like old things.” This isn’t an accusation but an appraisal, a way of coming to grips with who he is. “Greenberg” is an unsettling but ultimately joyous little picture, a movie that’s as self-conscious as anything Baumbach has ever made, and yet far more open: It reaches out to the world instead of insisting on hugging its own pain, tight. There are points in “Greenberg” where Roger treats Florence with inexcusable cruelty; he’s cruel to her, in fact, right after he proffers that heartfelt mix-CD. But slowly, gradually, he’s getting the hang of not hurting people. “Greenberg” is all about that halting, forward movement. Maybe there’s no happy ending for Roger Greenberg, but there’s no going back, either, and that counts as progress.

But sometimes the very movies that critics aren’t supposed to bother with — and act blasé about when they do — tell us more about what’s missing from American mainstream movies than about what’s in them. “Our Family Wedding” is a breezy, uncomplicated, unapologetically broad comedy that isn’t trying to be the next “Knocked Up” or “The Hangover”; that features a number of appealing actors who don’t show up in movies as often as they should (chiefly because they’re not white); and that shows us a world in which people of color aren’t necessarily struggling financially or dealing with drug problems or trying to stay out of jail.

The major point of conflict in “Our Family Wedding” — that the families are wary of each other because of cultural differences and their unshakable awareness of stereotypes — is exaggerated. But then, exaggeration is often a major ingredient of comedy, and “Our Family Wedding” never pretends it’s striving for nuance. That means there are elements of slapstick (including a goat who’s intended to be part of the wedding feast but who wreaks havoc on the stacked glassware and elegantly laid tables instead) and sequences in which the Latino guy and the black guy circle each other warily. When Whitaker’s character begins to boast, “Once you go black…,” Mencia’s character counters, under his breath, with “your credit goes bad.” The joke itself isn’t funny; what is interesting is the way each of these guys has so much invested in proving who’s lower on the totem pole, not just in terms of color but in terms of class. In fact, “Our Family Wedding” may have more to do with class than it does with color. Marcus is a physician who’s about to go to Laos with Doctors Without Borders, and he wants Lucia to go with him — hence the hasty marriage. Lucia has dropped out of Columbia Law School for reasons of her own, although her father, a mechanic who runs a lucrative towing business and garage in Los Angeles and who’s also highly skilled at restoring vintage cars, doesn’t know that yet. Marcus’ dad is a smooth-talking Los Angeles DJ (Whitaker’s smooth, purring voice is put to good use here) who’s been footloose and fancy-free for so long that he can’t see that his longtime best friend, a successful entertainment lawyer played by the charming, sly Regina King, is perfect for him. This isn’t a movie about disadvantaged people who want their children to do better than they’ve done; it’s about people who have worked hard and who want their kids to do at least as well as they’ve done.

But those are just undercurrents: “Our Family Wedding” isn’t a social tract but a comedy, and in places it gives in to rampant silliness. There’s a food fight involving wedding cake, and a straitlaced grandmother (played by the wonderful comic actress Lupe Ontiveros) who falls to the floor in shock and dismay when she sees her granddaughter walk through the door with a black guy. (When he politely tries to help her up, she slaps at him with the inefficiency of a baby seal.)

There are some weak links in “Our Family Wedding”: Mencia is a little stiff with his lines, and the picture (which was written by Wayne Conley, Malcolm Spellman and Famuyiwa) features not just one but two Viagra jokes, which is two too many. And the movie loses steam when, inevitably but of course temporarily, the two lovers are torn apart by their families’ differences. But Famuyiwa (who directed the 2002 romantic comedy “Brown Sugar”) gets us through that patch quite swiftly, and almost all of the performers here — including Ferrera, who’s characteristically appealing and fresh-looking — are completely in tune with the movie’s good-natured vibe.

Those words I mentioned earlier, “clichéd” and “formulaic,” are often used by critics and moviegoers to describe works that are a variation on things we’ve seen many times before. But what’s the difference between a cliché and a convention? Conventions are ideas — visual, musical, philosophical, whatever — that resurface in culture again and again, for reasons that we can’t always explain. Sometimes they’re merely convenient shorthand; other times they represent a deeper kind of shared language. And sometimes a convention is simply something that a lot of us can relate to: For example, the silly, frustrating things that can happen when two families are thrown together by a marriage. (Lord knows that never happens in families in which everyone is white.)

At the end of “Our Family Wedding,” the mariachi band hired by the bride’s family plays Babyface’s “Soon as I Get Home.” Is it a cliché to show Mexican guys in big embroidered sombreros performing an unlikely song, in this case one that supposedly “belongs” to black people? Maybe. But I think the larger point is that the song belongs to everybody.

The thanks he gets amounts to a blank gaze and a muddy restating of the nonfact in question. But Miller won’t be lulled into the becalmed state of believing everything he hears: He presses forward, to the point of disobeying orders, trying to uncover a truth that no one around him much cares about, simply because it threatens to disrupt their own ambitions and plans. His dogged earnestness is what gives “Green Zone” its sense of wayward, zigzaggy momentum: This is a movie that recognizes there’s no straight line to the truth, which is part of what makes it vaguely unsatisfying — though it’s also what keeps it honest.

“Green Zone” is fiction, a jittery, idealistic thriller adapted — by screenwriter Brian Helgeland — from elements of Rajiv Chandrasekaran’s 2006 exposé “Imperial Life in the Emerald City.” The director is Paul Greengrass, a filmmaker who has divided his time and attention between “serious” pictures (like the extraordinary “Bloody Sunday,” about the 1972 Derry massacre, and the beautifully crafted but excruciating “United 93″) and intelligent crowd-pleasers (like “The Bourne Supremacy” and “The Bourne Ultimatum”) that, whatever their flaws might be, at least feel like movies made for grown-ups. Similarly, “Green Zone” comes off as a picture made by a person with a brain as well as a conscience, though the movie’s big flaw may be its unblinking insistence that we’ve been lied to — you don’t have to read too much between the lines to see how adamant Greengrass is about that fact, though he isn’t telling us anything particularly new.

But I think the value of “Green Zone” lies less in what Greengrass is telling us than in the mood of helpless dread he takes so much care in building. Miller is an honest and good soldier, not a loose cannon: He’s completely willing to look for those WMD, even though he’s also become a bit ground down by the fact that he hasn’t been able to find any. His mistrust of a slippery-eel government lackey (played by Greg Kinnear, in yet another one of those slippery-eel roles he was born to play) leads him to get into bed — not literally, of course — with a CIA analyst (Brendan Gleeson) who fears that the United States’ plan to outlaw Saddam Hussein’s Baath party will lead to a bloody civil war. As he searches for what he hopes will be the truth — that note of uncertainty is intentional, the eternal question mark around which the whole movie revolves — he presses an Iraqi citizen, Freddy (Khalid Abdalla), into service. Freddy insists he only wants to help his country; the complication is that no one — least of all the U.S. military — knows what his country really needs.

Woven into a plot that’s often murkier and more convoluted than it needs to be is a journalist (Amy Ryan) who’s something of a stand-in for Judith Miller (except for the fact that this one actually has principles). Greengrass’ methods of visual storytelling aren’t as sharp as usual: He’s chosen to tell this story in faux-documentary style, which means he uses lots of “Bourne”-style shaky cam and jitterbug cutting. Greengrass generally takes extreme care to craft clear action sequences, in which it’s always possible to tell who’s coming from where. But the action in “Green Zone” is sometimes uncharacteristically wayward and confusing. And while Greengrass may have been, up to this point, one of the most skillful users of the hand-held camera, there’s nothing particularly interesting or effective about its use in “Green Zone.” Keeping the camera stationary would have been a far more surprising and suitable choice.

Still, “Green Zone” shows an emotional rawness that’s likely to hit home for anyone who still feels shafted by the U.S. government’s ineptitude in Iraq. This is a movie made up of exposed nerve endings; it never capitulates to the idea that it’s OK to smooth out the facts. In his forward to the recent paperback edition of Chandrasekaran’s book, Greengrass writes, “Sometime in early 2004, I began work on a film set in Iraq. I wanted it to be a thriller — urgent, contemporary, filled with intrigue: A movie that would hopefully take some of the huge audience that had enjoyed the Bourne series to a real-world setting and encourage them to consider whether the mistrust and paranoia that characterized Bourne’s world was so far-fetched after all.” And while I find myself repeatedly asking myself if Matt Damon really is all that good an actor, watching him in “Green Zone” reminded me that there’s a particular type of guileless, principled guy that he often plays perfectly. In that respect, his Roy Miller is a lot like Jason Bourne, a man who’s been trained to be a tool of the system but who insists on thinking for himself — not to be contrarian but as a way of staying true to some standard of decency he’s set for himself. Near the end of “Green Zone,” we see Damon’s Miller, weighed down by full combat gear, getting ready to leave the luxury room, located in an appropriated palace, where he’s temporarily set up operations. Damon, with his all-American honest-lad good looks — not to mention his sand-colored fatigues and combat boots — looks out of place amid all that grandeur. And somehow — even though his face wears the dutiful blank expression of a good soldier — he also looks disgusted by it.

Is a seemingly casual performance harder to pull off than a mannered or highly stylized one? The answer to that question has as many variations as there are actors, but the fact that Bridges’ “Crazy Heart” performance feels so breezy and natural shouldn’t cause anyone to underestimate it. This performance doesn’t come out of left field for Bridges — it comes out of the field, which is to say it springs from a lifetime spent giving terrific performances in good movies as well as mediocre ones, as Bridges has done. Bridges has been great in many terrific movies (“The Fabulous Baker Boys,” “The Fisher King,” “The Big Lebowski”), but it’s hard to think of even a bad movie in which he’s been bad. His presence has elevated otherwise lousy pictures — “Starman,” for instance — into works that can’t be wholly dismissed. There are few other actors who have been so consistently good and also, strangely, so consistently invisible.

I don’t mean that audiences have been blind to Bridges’ gifts: In the month since the Oscar nominations have been announced, I haven’t run into a single person who openly hopes he doesn’t win. (I’m sure that person is out there, but I don’t want to meet him.) But Bridges is so understated as an actor that perhaps it’s been easy to take him for granted, which is why it’s fitting that he should make the biggest splash of his career in a small picture that arrived practically out of nowhere. “Crazy Heart,” written and directed by first-timer Scott Cooper (and adapted from a novel by Thomas Cobb), was hustled into a quick pre-Christmas release by its studio, Fox Searchlight. Obviously, some execs there saw the strength of Bridges’ performance and thought it might attract Oscar consideration.

Heartfelt appreciation of the actor’s craft or crass marketing decision? Who cares? It doesn’t matter, as long as he wins. In “Crazy Heart,” Bridges plays Bad Blake, a sozzled has-been who meets Jeannie (Maggie Gyllenhaal), a journalist and single mom who coaxes him, without even trying, into straightening his life out. I’ve heard, as you probably have, “Crazy Heart” described as your typical “washed-up performer saved by the love of a good woman” narrative. But even though the story told in “Crazy Heart” is quite simple, I don’t think there’s anything typical about it. For one thing, it doesn’t stoop to giving us a sappy ending. And Gyllenhaal, as a romantic match for Bridges, isn’t a boilerplate character. You can look at this woman and think you’ve seen her before, but Gyllenhaal — in the way she here and there shows a flicker of exasperation, or shifts between guardedness and wholehearted openness within the space of a few frames — plays Jeannie with a searching forthrightness that always feels honest.

She also challenges Bridges, pushes against him, giving him a range of actions and believable emotions to respond to. I marveled the first time I watched Bridges’ performance, but I couldn’t even begin to parse what he was doing to shape the role. The second time I watched, I had even worse luck — whatever it is Bridges is doing here, it keeps slipping through my fingers like water. In some scenes, his enunciation is intentionally lousy: Explaining to Jeannie why he quit one of his earlier enthusiasms, playing baseball, he says, “Figured I’d stick with the guitar, sumbitch stayed where it’s supposed to.” You can understand him perfectly — this is hardly a drunken slur — and yet the line has a slippery-graceful texture, like a garden snake darting behind a stone wall. With just a line, Bridges clues us in to what makes Bad an artist and not just a drunken lout who’s had a few lucky breaks. He’s the hard-living manifestation of Warren Beatty’s mumbly frontiersman line from “McCabe and Mrs. Miller”: “I got poetry in me!”

This is also a performance with no vanity. Time and again Bridges’ Bad will plunk himself down on a couch, or sprawl on a hotel bed, his threadbare shirt left open to reveal a somewhat soft-looking, whitish belly. That belly isn’t sexy, and it’s not unsexy: It’s just there, an unself-conscious declaration — “This is where I’m at now.” This is acting, of course — by now we’ve all seen how sweet and well-groomed Bridges looks when he shows up for an awards event — but here he’s so fully slipped into the character’s skin that it’s indistinguishable from his own.

And Bad’s rubbery smile — a smile that sometimes comes out of nowhere, like a naughty secret — is killer. That smile is what makes one of the movie’s darker moments — when Bad, after a night of drinking, pukes into the toilet and then curls up on his bathroom floor, whimpering in self-loathing — so anguishing. To see Bad that miserable is pain itself; he’s got to get that smile back, or we’ll be the ones to suffer. That’s the secret, maybe, of “Crazy Heart”: On its most base level, it probably is your stock redemption story. But this is Jeff Bridges we’re talking about, an actor who makes every gesture, every offhanded expression, so effortlessly believable that to watch him in anguish is almost unbearable. Late in “Crazy Heart,” Bridges — who does his own singing throughout the movie, in a voice with the hearty, mellow quality of barbecue smoke — performs a song with the line “This ain’t no place for the weary kind.” It’s a song about not stopping, even when you think you’re through, a staple idea in the country-music canon. Bridges’ work in “Crazy Heart” is just one astonishing performance among the many he’s already given. But maybe it’s the one that best pulls together all of the things so many of us love about him — the way the poetry in him seems so plainspoken, even though it has no words.