TONIGHT'S MUST-SEE

"ER," 9:01 p.m., NBC. This show has wobbled lately. But now comes its 300th episode and a time to remember what it has been. "ER" arrived in 1994 with stunning talent off-camera (Steven Spielberg as producer, Michael Crichton as creator) and on. (Somehow, the world had never realized that George Clooney is a star.) It used TV's best directors. Cameras swirled as life-and-death stories were told. "ER" won 22 Emmys and a Peabody. The stories later sagged, but we can hope for a comeback tonight: Luka and Abby must rush to Croatia. A husband (Peter Fonda) rushes to the waiting room, then finds a surprise.

"Grey's Anatomy," 8 p.m., ABC. After pausing for a week, this show wraps up its two-parter. Meredith is struggling to save the paramedic trapped in the ambulance. Her half-sister, a first-year resident, suddenly has a life-or-death situation.

OF NOTE

"Once Upon a Christmas" (2000, 7 p.m.) and "Twice Upon a Christmas" (2001, 9 p.m.), ABC Family. The first film is sweet and enjoyable, as Santa's daughter (Kathy Ireland) becomes fond of a mortal family. The second has a neat satiric touch, as her evil sister Rudolfa tries to sell the North Pole. There's good work throughout, including Shakespearean actor Douglas Campbell as Santa in the first film and Mary Donnelly Haskell as Rudolfa in both.

"Survivor: China," 7 p.m., CBS. After tonight's episode, there will only be one more before the Dec. 16 finale.

"My Name is Earl," 7 p.m., NBC. When the warden goes back on his promise of an early release, Earl hatches his own release plan: He'll have his daft friends help with an escape.

"30 Rock," 7:30 p.m., NBC. Jack's girlfriend (Edie Falco) wants to be public about their romance; Jack, alas, doesn't want to admit he's dating a Democrat. Meanwhile, Liz faces the duelling wrath of Tracy and Jenna.

"The Office," 8 p.m., NBC. There are funny moments in this rerun, especially when Michael tells college kids that paper will always be important.

"CSI: Crime Scene Investigation," 8 p.m., CBS. William Friedkin, the acclaimed director of "The French Connection" and "The Exorcist," directed this episode in which Warrick, sinking into pill addiction, is a murder suspect.

"Scrubs," 8:30 p.m., NBC. When patients get to rate their doctors online, a nasty competition begins.

"The 10 Most Fascinating People of 2007," 9 p.m., ABC. Barbara Walters dubs Don Imus as fascinating (really) and gets his first interview since he was fired in April. She talks to people who really are interesting (Bill Clinton, Jennifer Hudson, Katherine Heigl, the MySpace founders) or who are supposed to be (Justin Timberlake, David and Victoria Beckham). She also names someone as the No. 1 most fascinating.