Series
The Biggest Loser: : Tim Gunn of Project Runway helps the contestants look their best after they receive makeovers. (8 p.m., WBAL-Channel 11)
American Idol: : Director Quentin Tarantino guides contestants in their performances of songs of the cinema. (8 p.m., WBFF-Channel 45)
90210: : Kelly and Silver (Jennie Garth, Jessica Stroup) get an unexpected visit from Donna Martin (Tori Spelling). (9 p.m., WNUV-Channel 54)
Frontline/World: : In "Children of the Taliban," correspondent Sharmeen Obaid looks into the increasing power and influence of a new branch of the Taliban in Pakistan. (9 p.m., MPT-Channels 22/67)
Deadliest Catch: : As the reality series returns for Season 5, there's more white-knuckle seafaring in store as the crews of the fishing boats compete to pull in the biggest catches of Alaskan king crab. (9 p.m., Discovery)
Late-night guests
The Tonight Show with Jay Leno:: Jamie Foxx. (11:35 p.m., WBAL-Channel 11)
Late Show with David Letterman:: Kelly Ripa; the Yeah Yeah Yeahs perform. (11:35 p.m., WJZ-Channel 13)
