TONIGHT'S MUST-SEE

"American Experience: Jonestown: The Life and Death of Peoples Temple," 9 p.m., PBS. If Jim Jones had simply been a mad man, this might not be interesting. But there's also the story of his original appeal. In a race-conscious world, Jones merged blacks and whites. He brought the joy of a hand-clapping, praise-singing church. He spoke of sharing and community. Then he gradually went crazy, leading to the 1978 deaths of 909 followers in a Guyana jungle. People who were there recall this story calmly and clearly. Many, including his adopted son, were members of Jones' church. They recall the power he once held.

"Thank God You're Here" debut, 8 and 9 p.m., NBC. Improvised comedy gets a fresh twist here. Each actor is rushed into a scene he knows nothing about. In the opener, all four — Jennifer Coolidge, Bryan Cranston, Wayne Knight, Joel McHale — do well. David Alan Grier hosts, and Dave Foley is witty as the judge. Some of the best moments come in alternate bits, with each actor stepping into the same situation. Also, in a late change, NBC is inserting the second episode instead of "Black Donellys." The improv guests are Jason Alexander, Jane Lynch, Harland Williams and Brian Posehn.

OF NOTE

"Falcon Beach" season opener, 7 p.m., ABC Family. This Canadian series offers attractive young actors, a pretty setting and an odd blend of solid drama and soap-style overkill. Last season, we saw this beach town through newcomer Paige, a blonde beauty. As this season begins, she's thought to be in college, abandoning Jason, the handsome townie. Her dad (the soapiest part of this show) bought the family cottage, evicting his own wife; now he plans to turn the town into a trendy retreat. Meanwhile, Tanya awaits a court appearance, and Erin and Daddy await their baby. Despite its excesses, "Falcon Beach" is worth watching.

"Dancing With the Stars," 7 p.m., ABC. Viewers have been tough on beautiful women. Last week, they ousted Shandi Finnessey, the former Miss USA; the week before, it was Paulina Porizkova, the former supermodel. Now the final nine compete.

"How I Met Your Mother," 7 p.m., CBS. Barney ruins Marshall's bachelor party. Now he may be dumped him as the best man.

"The New Adventures of Old Christine," 7:30 p.m., CBS. Christine has been enamored by her son's handsome teacher (Blair Underwood). She talks about him in an e-mail that accidentally goes to all the parents.

"Two and a Half Men," 8 p.m., CBS. Charlie finds himself attracted to Judith's future sister-in-law, who is not his usual type.

"King of Queens" season opener, 8:30 p.m., CBS. Here is the show's 200th episode and the start of its brief (seven-episode) final season. Don't expect any huge laughs; it's a fairly funny episode, with sympathetic characters. When she hears that her friends have a vacation home, Carrie (Leah Remini) is jealous and bitter. She demands that Kevin (Doug James) explain why they don't have one.