TONIGHT'S MUST-SEE

"30 Rock," 7:30 p.m., NBC. Here's another fast, fun episode. It's not as good as last week's season opener, but still way above average. Jack is pushing for the top GE job, while trying to conceal the fact that he had a heart attack. Liz hears lectures about her empty life, and Jenna is starting to enjoy the attention she gets from being overweight. Meanwhile, there are efforts to get Tracy and his wife (Sherri Shepherd) back together.

"Grey's Anatomy," 8 p.m., ABC. The good news for George is that all the other interns think he's remarkably skilled. The bad news is they don't realize he flunked and is repeating the whole residency. And the worse news? He still has to tell his wife, Callie, about his romance with Izzie. We haven't seen this hour but last week's was excellent. The other complication involves Meredith's reluctance to work with her half-sister, Lexie. Tonight, they share an emergency case.

OF NOTE

"Ugly Betty," 7 p.m., ABC. Freddy Rodriguez, who was so good in "Six Feet Under," plays a sandwich vendor who visits the office, stirring Betty's feelings. Meanwhile, her colleagues are excited about the black-and-white ball.

"My Name is Earl," 7 p.m., NBC. Michael Rapaport guests as a fellow prisoner. He relates a long story that includes both Earl and Joy.

"Mad Men," 7 p.m., AMC. After molding Richard Nixon's 1960 presidential ads, the colleagues settle in for an all-nighter, to follow the election results. We won't spoil it by telling you who wins.

"It's Always Sunny in Philadelphia," 7 and 7:30 p.m., FX. The first episode has Dee dating a rapper; that inspires the guys to form their own band. The second has Dee learning to box, after being mugged; soon, Charlie is street fighting.

"Twitches" (2005), 8 p.m., Disney Channel. Everyone likes a 21st-birthday surprise, but this may be a bit much. Two women (Tia and Tamera Mowry) learn they're twins. And they're princesses in an alternate world, with magic powers. The result is a fun movie. Its sequel — only so-so — debuts Friday through Sunday.

"The Office," 8 p.m., NBC. The launch of the company's Web site brings parties at headquarters and in Scranton. Meanwhile, Dwight tries to prove he can outsell the site; it's kind of like the John Henry story, maybe.

"CSI: Crime Scene Investigation," 8 p.m., CBS. Everyone in a family was slain except the daughter, who may think she's possessed by the devil.

"Without a Trace," 9 p.m., CBS. A missing woman may have gone to Guatemala, where she feels her son is a hostage.

"ER," 9 p.m., NBC. The staff hustles to save volunteer cops who were shot, a kid who has a deadly disease and a wrestler who is vomiting.