America's Got Talent

America's Got Talent
8/7c NBC
A contortionist break-dancer. An opera singer. A tenor trio. A golden-girl comic. Power tap-dancing siblings. These ace entertainers are among the final 10 acts who took the stage in Monday's last-chance performance episode. With tension spiking and nerves popping, they are now in line to score the big $1 million prize and a headlining Vegas show. With the big-stage curtain finally closing on the sprawling star search, one of them will be named the winner in tonight's two-hour Season 4 finale. Performers include Britain's Got Talent phenom Susan Boyle, pop songstress Shakira, English singer Leona Lewis, country stars Rascal Flatts and high-flying act Cirque du Soleil. — Dean Maurer

The Beautiful Life: TBL
9/8c CW
After a rough summer that included a stint in a psychiatric ward, Mischa Barton makes her return to network television in this sexy new drama about the New York modeling world, which exec producer Ashton Kutcher says will be a more accurate portrayal of the fashion industry than the "sanitized" version we've seen on some reality shows. Barton plays veteran model Sonja Stone, who gets upstaged by newcomer Raina Marinelli (Sara Paxton) in the series opener. Elle Macpherson and High School Musical alum Corbin Bleu also star. — Karen Andzejewicz

Live from Lincoln Center
8/7c PBS
The New York Philharmonic opens the 2009-10 season under the baton of new music director Alan Gilbert, the first native New Yorker to hold the post. Selections include an overture by composer-in-residence Magnus Lindberg, Berlioz' Symphonie Fantastique and Messiaen's Poèmes pour Mi, featuring soprano Renée Fleming. Alec Baldwin hosts. — Jeff Gemmill

Glee
9/8c Fox
So far, the glee club hasn't felt much love around McKinley High, and don't look for that to change anytime soon. In fact, even Will neglects the kids tonight (the girls, anyhow — he's forming an all-male a capella group), and when Mercedes falls in love she doesn't exactly get the response she seeks. Josh Groban has a cameo as himself, lending moral support to Will's new group, the Acafellas, and Victor Garber begins his recurring role as Will's dad. — Paul Droesch

Top Chef: Las Vegas
10/9c Bravo
It was a French connection in the previous episode when our food fighters served up delicate French fare. (Hector got French dissed due to his ill-cooked beef. Au revoir, Hector.) This leads us to tonight's challenge, an affair that turns campy when the foodies visit a campsite and concoct a menu for a collection of Las Vegas cowboys. The heat is on, especially when cooking outside in blazing temperatures, and it appears that ace taste tester Tom Colicchio has to spit out some food in disgust. That's going to be hard to swallow for one contestant. — Dean Maurer

Biography
10/9c Biography
George Clooney started small in the 1984-85 sitcom E/R, but it was his role as Dr. Doug Ross in the NBC drama ER that made the actor a star. This profile of Clooney looks beyond his roles as a TV heartthrob, director and Oscar-winning actor, and explores the life of a man who is also known for his outspoken views and actions as a social activist. — Bill Ecklund