TONIGHT'S MUST-SEE

"Worst Week" debut, 9:30 p.m., CBS. Sam is a likable chap at a turning point. He and his girlfriend plan to tell her parents that she's pregnant. Naturally, he bumbles everything — TV guys always do. The original, BBC version (now on DVD) had all the advantages. It had a limited run and played off the class consciousness in England. This version makes do by cranking things up a few notches. Sam (Kyle Bornheimer) errs hugely and hilariously. We know the feeling.

TONIGHT'S MIGHT-SEE

"Heroes," 8-10 p.m., plus preview at 7 p.m., NBC. We quickly learn (or think we do) who shot Nathan. Then the plot propels quickly, while running into a problem. Yes, this has all the "Heroes" qualities. The characters and situations are wonderfully imaginative. Still, their powers are so extreme that the story lacks bite. How do you stop people who can transcend time and space?

OF NOTE

"Dancing With the Stars," 7-9 p.m., ABC. We meet the 13 new stars, ranging in age from 18 (Cody Linley) to 82 (Cloris Leachman). In accomplishment, they range from Olympic champions Maurice Greene (sprint) and Misty May-Treanor (beach volleyball) to ... well, rich kid Kim Kardashian.

"Big Bang Theory" season opener, 7 p.m., CBS. Among his many social flaws, Sheldon is incapable of keeping a secret. Penny tells him one, with hilarious results.

"How I Met Your Mother," 7:30 p.m., CBS. As last season ended, Ted asked Stella to marry him. In a very funny season opener, we get the aftershocks and a new crisis: Barney loves Robin.

"Two and a Half Men," 8 p.m., CBS. An ex-girlfriend's son looks a lot like Charlie.

"CSI: Miami," 9 p.m., CBS. As last season ended, Horatio was shot at an airfield. We learn what happened in an hour that balances overwrought writing with drab, robotic acting.

"Boston Legal," 9:01 p.m., ABC. This season has reruns at 8 p.m. Mondays on ION (tonight, Freddie Prinze Jr. arrives) and the final 13 new ones on ABC. Tonight, Alan helps little Bethany fight a tobacco company.