Buffy battles Glory in the season finale of Buffy the Vampire Slayer (8 p.m., WB). This is the last episode on the WB; it's also the 100th episode of the series, which means the reruns are now eligible for syndication. Something monumental may or many not happen tonight; there are rumors of one or more significant characters biting the dust, but no one associated with the show will say for sure. 3rd Rock from the Sun (8 p.m., NBC) ends its run after six seasons -- as if anybody will notice. It's an hour-long episode and Elvis Costello (!) has a cameo. It's Mac's wedding day on the season finale of JAG (8 p.m., CBS), but not if Harm can help it. On the season ending episode of Dark Angel (9 p.m., Fox), Max is captured by Lydecker, but it seems that he's the one in bigger trouble. Frasier (9 p.m., NBC) closes out the season with back-to-back episodes. In the second (9:30), the gang jets off to Belize for a getaway, where a figure from Frasier's past manages to find him. On the season finale of Angel (9 p.m., WB), Angel, Cordelia, Wesley, Gunn and the disembodied, talking head of the Host frantically search for a portal to take them back home. Amy presides over a volatile custody case and Vincent contemplates a move on the season finale of Judging Amy (10 p.m., CBS). Danny is missing, his stripper girlfriend is dead and Andy thinks his little pal is in a heap o' trouble on the season finale of NYPD Blue (10 p.m., ABC).
Braves at Marlins (7 p.m., TBS)
Bucks at 76ers, Game 1 (8:30 p.m., TNT)
Penguins at Devils, Game 5 (7 p.m., ESPN)
Rosie O'Donnell (syndicated) Martin Sheen, Missy Elliot
David Letterman (CBS) Ellen DeGeneres
Jay Leno (NBC) Martin Lawrence, Colleen Haskell
Politically Incorrect (ABC) Al Franken, Holland Taylor
Conan O'Brien (NBC) John Lithgow
Craig Kilborn (CBS) Jennifer Tilly, David Gray
All times Eastern unless noted.