Will Arnett, Lisa Lampanelli, Guided by Voices

Brian Williams, WU LYF

Tina Fey, Barr Brothers

Kristen Bell, Dan Naturman, Blind Pilot

Mark Wahlberg, Heather Morris, Snow Patrol

Kate Beckinsale, Marv Albert, the Little Willies

Dolly Parton, Alan Zweibel

Johnny Winter

Viggo Mortensen, Tony Bennett

Simon Baker, Elizabeth Banks, Seal

Ricky Gervais, Kathleen Edwards

Marg Helgenberger, Ellie Goulding

Kathy Griffin, Joseph Arthur

Dana Carvey, Los Campesinos!

Jennifer Lopez, Rob Schneider, James McCartney

Stephen Merchant, Girls\' Generation

Howard Stern, the Airborne Toxic Event

Woody Harrelson, Lana Del Rey

Michelle Williams, Jake Johannsen, Ziggy Marley

Sarah Michelle Gellar, Joe Scarborough, Die Antwoord

Denzel Washington, the Fray

Ryan Reynolds, Ellie Kemper, Dierks Bentley

Nicolas Cage, thehugs

David Spade, Betty Wright

Reese Witherspoon, Michael Weatherly, a Top Ten List presented by Sports Illustrated Swimsuit models, Kasabian

Viola Davis, the 2012 Sports Illustrated Swimsuit cover model, Mark Ronson, Erykah Badu, the Dap-Kings, Zigaboo Modeliste

Jon Stewart, Yelawolf with Kid Rock

Joan Rivers, Andrew Lincoln

Kristen Wiig, Butch Walker

Jack Hanna, Jesse Tyler Ferguson

Alec Baldwin, Eric Hutchinson

Paul Rudd, John Witherspoon, Heartless Bastards

K\'naan featuring Nelly Furtado

Matthew Broderick, Nick Griffin, We Are Augustines

Ed Helms, Dan Patrick, Lyle Lovett

Nathan Lane, Estelle

Neil Patrick Harris, Taylor Kitsch, Robert Glasper Experiment featuring Lupe Fiasco & Bilal

Jon Hamm, White Rabbits

Actor Will Ferrell; actor Jon Bernthal.

Amanda Peet; Nick Offerman; The Chieftains; The Low Anthem; Cee Lo Green presents the Top Ten.

Actor Martin Short; The Ting Tings perform.

Michelle Obama, Esperanza Spalding

Jennifer Lawrence, Gail Collins, the Shins

Debra Messing, Josh Hutcherson, Oberhofer

Rachel Maddow, Timothy Olyphant, Train

Jason Sudeikis, Lionel Richie, Jason Aldean

Chris Elliott, Mohamed Nasheed, Justin Townes Earle

Jim Rome, a performance from the Broadway musical \"Once\"

Megan Mullally, Band of Skulls

Coming soon...

Seth Meyers, Allison Williams, Lukas Nelson & Promise of the Real

Kiefer Sutherland, Eugene Levy, the Punch Brothers

Ricky Gervais, Cobie Smulders, Tennis

Sean Hayes, Jim Gaffigan, Shooter Jennings

Magic Johnson, Larry Bird, Kaiser Chiefs

Billy Crystal, Alabama Shakes

Julia Louis-Dreyfus, Bonnie Raitt

Jason Segel, Zach Wahls

Amy Poehler, Wendy Williams, Trampled by Turtles

Rob Lowe, Gov. Brian Schweitzer, the War on Drugs

Robin Williams, Andrew Luck

Chris Hemsworth, Darrell Hammond, Miike Snow

Don Rickles, Carrie Underwood

Seth Meyers, Father John Misty

Stupid Pet Tricks, Johnny Galecki, Norah Jones

Stephen Colbert, Chloe Grace Moretz, a performance by the Broadway cast of \"Nice Work If You Can Get It\"

Anderson Cooper, Yves Rossy, Electric Guest

Dr. Phil McGraw, Beth Behrs, Spiritualized

Jim Parsons, Mika Brzezinski, Macy Gray

Eva Longoria, Tom Dreesen, Florence and the Machine

Kid Scientists, Elizabeth Banks, Edward Sharpe & the Magnetic Zeros

Jon Cryer, Tommy Johnagin, M. Ward

Kelly Ripa, Adam Scott, Tenacious D

Brian Williams, El-P

Betty White, Best Coast

Conan O\'Brien, Regina Spektor, John Mayer

Julie Chen, Beach House

Lea Michele, Barry Sonnenfeld

Will Smith, Gossip

Piedmont Bird Callers, Bill O\'Reilly, Pitbull

Joan Rivers, the winner of the Indianapolis 500, Silversun Pickups

Neil Patrick Harris, Noomi Rapace, Alan Jackson

Jane Fonda, Mayor of London Boris Johnson, Jimmy Cliff

Bill Murray, the Temper Trap

Mark Wahlberg, Sebastian Vettel, Black Box Revelation

Jack Hanna, Patti Smith, Bootsy Collins

Adam Sandler, Jerry Douglas

TV host Regis Philbin; comic Lenny Marcus; Elizabeth Cook performs.

Actor Denis Leary; actress Olivia Wilde; The Pierces perform.

Actor Jeff Daniels; actor Benjamin Walker; Walk the Moon performs.

Actor Alec Baldwin; Mike Kiwanuka performs.

Singer Justin Beiber; actor and comic Michale Ian Black.

Emma Stone, Jimmie Walker, Diamond Rugs

LeBron James, Maroon 5

Channing Tatum, the Gaslight Anthem

Andrew Garfield, Drew Brees, Animal Collective

Ray Romano, Tom Waits, a Top Ten List presented by American League All-Stars

Queen Latifah, Fred Armisen, Cory Chisel, Buddy Guy

Bryan Cranston, R.A. Dickey, Zac Brown Band

Anne Hathaway, Moody McCarthy, Loudon Wainwright III

Michael Caine, Gallagher, Nas

Roseanne Barr, Aubrey Plaza, Jeff the Brotherhood

Kyra Sedgwick, Red Wanting Blue

Woody Harrelson, Grafitti6

Will Ferrell, Rufus Wainwright

Zach Galifianakis, former U.S. Army Sgt. Valerie Brown, Allen Stone

Jonah Hill, Dr. Leonard Girardi, Milo Greene

Joel McHale, Andrew Norelli, will.i.am

Andy Samberg, Ashton Eaton, Glen Hansard

The U.S. Women's Olympic Gymnastics team, Jennifer Garner, Rodriguez

Tom Brokaw, Dana Vollmer, a Top Ten List presented by Lionel Richie, Rick Ross

Tracy Morgan, Erik Kynard, Ben Howard

Kelsey Grammer, Olivia Munn, Train

Bill Hader, Mary Louise Parker, the Walkmen

Serena Williams, Elle King

Kathy Griffin, Michael Somerville, Josh Turner