TONIGHT'S MUST-SEE:

"Survivor" "American Idol" (8 p.m., Fox). The two reality giants go back-to-back this week. For "Idol," this is the regular spot. Tonight it trims to the final 10, the ones who are on the show's summer mega-tour. For "Survivor," it's temporary. The show vacates Thursdays, to make room for the college basketball tournament.

OF NOTE

"High School Reunion," 7 p.m., TV Land. Last week's episode (rerunning at 8 p.m.) ended with Steve's arrival. Now, he settles in now, upsetting Mike. As Mike tells it, they were best friends and Steve was staying at his home - without mentioning that he was dating Mike's ex-wife, Lana. All three are there now, leaving raw emotions. Otherwise, things are sunny in this 20-year reunion of Texas classmates.

"My Big Fat Greek Wedding" (2002), 7 p.m. and 9 p.m., ABC Family. Nia Vardalos' one-woman show was turned into this amiable comedy. Vardalos stars opposite John Corbett.

"Law & Order: Criminal Intent," 7 and 8 p.m., NBC. In the first hour, Goren (Vincent D'Onofrio) tries some dangerous undercover work in a prison's mental ward. In the second, Logan and Falacci investigate, when a woman is killed before testifying in a rape trial.

"Great Performances: Eric Clapton's Crossroads Guitar Festival Chicago," 8 p.m., PBS. Here's a rerun of a great concert. The guitar masters are there (B.B. King, Buddy Guy, Vince Gill, Johnny Winter), plus Willie Nelson, Sheryl Crow, John Mayer and more.

"In Treatment," 6:30 p.m., HBO. Sophie, the teen gymnast, crumbles with doubts.

"Law & Order," 9 p.m., NBC. A gallery owner has been stoned to death after an exhibit drew religious controversy.

"Men in Trees," 9 p.m., ABC. Marin and Jack go to New York with Jerome, for Jane and Sam's post-wedding party.

"Lewis Black's Root of All Evil," 7:30 p.m., Comedy Central. This episode is far better than the debut one, because the targets are funnier. Greg Giraldo and Andy Kindler argue over which is more evil, Viagra or Donald Trump.