Hayden Panettiere visiting Letterman, Alanis Morissette hanging with Conan

"Letterman" and "Conan" both new tonight...

"Late Show with David Letterman": Hayden Panettiere, Joel McHale

"The Tonight Show with Conan O'Brien": Howie Mandel, Alanis Morissette

"Late Night with Jimmy Fallon": Andy Samberg, Jorge Garcia (repeat)

"Last Call with Carson Daly": Jimmy Fallon (repeat)

"The View": Larry Miller

"Live with Regis and Kelly": Mary McCormack

"The Ellen DeGeneres Show": Patrick Dempsey (repeat)

"The Bonnie Hunt Show": Dave Annable (repeat)