Here's who's on the late night shows tonight.

• Charlie Rose: coverage of the Pennsylvania Primary
• The Daily Show: John Waters
• The Colbert Report: Susan Jacoby
• The Late Show with David Letterman: Helen Hunt, Chris Russo, and Kathleen Edwards
• Jay Leno: Julia Louis-Dreyfus, Jason Segel, and Goldfrapp
• Jimmy Kimmel Live: Brad Garrett and Paul Thorn
• Tavis Smiley: E. Benjamin Skinner and Don Siegelman
• Late Night with Conan O'Brien: Andy Richter, Jennifer Esposito, and She & Him
• The Late, Late Show with Craig Ferguson: Laurence Fishburne, Rashida Jones, and Joe DeVito (repeat)
• Last Call with Carson Daly: Jack McBrayer

• At 8, ABC has a new According To Jim.
• CBS has a new NCIS at 8, then a new Big Brother.
• FOX has new episodes of American Idol and Hell's Kitchen.
• The CW has a new Beauty and the Geek at 8, followed by a new Reaper.
• There's a new Nova on PBS at 8.
• At 9, ABC has a new Dancing with the Stars, then a new Boston Legal.
• Discovery has a new Deadliest Catch at 9.
• Lifetime has the new movie Queen Sized at 9.
• Bravo has a new Real Housewives of New York City at 9, followed by the season premiere of Work Out.
• Sundance has Big Ideas For A Small Planet at 9.
• MTV has the season premiere of Tila Tequila: A Shot At Love 2 at 9.
• Also at 9: BBC America has a new Last Restaurant Standing.
• At 10, NBC has a new Law and Order: SVU.
• FX has a new episode of The Riches at 10.

Check your local TV listings for more.