TONIGHT'S MUST-SEE

"Samantha Who?" debut, 8:30 p.m., ABC. A young woman revives after days in a coma. She remembers nothing, recognizes no one. Sam soon learns that her mom is self-centered, her dad is drolly detached, one friend is uncaring and the other is a fake. The boyfriend is in a state of perplexed disinterest. The richer surprises are about Sam. We assume a central character (especially a cute one) will be a nice person; that's wonderfully wrong.

"Two and a Half Men," 8 p.m. CBS. In a clever episode last week, Charlie actually dated a smart woman (a judge, played by Ming-Na) his age. He flubbed the date, then obsessed on her. Tonight, he's still trying for another chance.

OF NOTE

"Chuck," 7 p.m., NBC. Who knew the CIA hired beautiful women as their spies? Tonight, Sarah's colleague asks for help. Chuck is distracted by both women; his friend Josh wants to date the new one. And there's the matter of a stolen diamond that must be stolen back.

"How I Met Your Mother," 7 p.m., CBS. Robin is getting close to her boyfriend's child. This makes her nervous.

"The Big Bang Theory," 7:30 p.m., CBS. When, Sheldon loses his physics job, he sort of enjoys real life (especially with Penny). Then he retreats in despair; Leonard contacts Sheldon's mother (Laurie Metcalf).

"Heroes," 8 p.m., NBC. We learn more about the previous generation of people with special abilities. Meanwhile, Matt wants little Molly to help locate the bogeyman. Claire's stepdad sees big trouble, if she's dating someone. Monica Dawson discovers a new ability her family doesn't know about.

"The Mysterious Human Heart," 9 p.m., PBS (concludes next Monday). Here's an adequate documentary, from producer David Grubin. His first hour traces two people awaiting transplants; the second views the heart's electric rhythms and what happens when they are genetically flawed.

"Journeyman," 9 p.m., NBC. Dan's wife is ready for a big charity event, when (as usual) he goes missing. He's back in 1995, helping a woman who's going out on a blind date.