Justin Bieber, Hugh Jackman

Jamie Foxx, Rosemarie DeWitt, One Direction

Megan Fox, Eddie Redmayne, Bethenny Frankel

Bradley Cooper, Bruno Mars

Anne Hathaway, Cee-Lo Green

Hugh Jackman, Justin Bieber

Amanda Seyfried, Usher

Howie Mandel, Tom Shadyac, Idina Menzel

Naomi Watts, J.R. Martinez

Fergie, Nathan Lane

Christina Aguilera

Drew Barrymore, Cory Monteith

John Travolta, Olivia Newton-John, Mario Lopez

Gerard Butler, Giada De Laurentiis, Martha Plimpton

Jessica Biel, Damon Wayans Jr.

Wanda Sykes, Kevin Pollak

Tim Allen, Kunal Nayyar, Maroon 5

Khloe Kardashian, Damian Lewis, Jane Lynch

Ellen Pompeo, Jason Sudeikis, Miguel

Ray Romano, Stephen "tWitch" Boss, Cirque du Soleil's Iris

Jennifer Lawrence

Jesse Tyler Ferguson, Kelly Clarkson

Alyson Hannigan

Vanessa Williams, Jason Aldean

Keira Knightley, One Direction

Rihanna, Blue Man Group

Andrew Garfield, Alison Eastwood & Donald Schultz, Ne-Yo

Adam Levine, Jennifer Hudson, Maroon 5

Robert Pattinson, Taylor Lautner, Kirstie Alley

Miley Cyrus, Maggie Grace, Jackson Rathbone

Bethenny Frankel, Russell Brand

Heidi Klum, Nikki Read, Mackenzie Foy

Julie Bowen, Peter Facinelli, Elizabeth Reaser

Denzel Washington, Jenna Fischer, Luke Bryan

Emmitt Smith, Cheryl Burke

Jane Lynch

Steve Harvey, Macklemore & Ryan Lewis

Madonna

Halle Berry

Taylor Swift

Helen Hunt, Mason Cook

Portia De Rossi, Jerry O'Connell, LL Cool J, Victoria Jackson & Ali Guthy

Jessica Lange, Beth Behrs, Hunter Hayes

Nicole Richie, Nina Conti

Matthew Fox, Ellie Goulding

Emma Watson, Kym Douglas, D.L. Hughley, the Wallflowers

Joel McHale, Sabrina Bryan & Louis Van Amstel, the Script with will.i.am

Kate Walsh, Mike Epps, Anthony Robles

Bethenny Frankel, Octavia Spencer

Eric Stonestreet, Rachel Maddow, Joshua Radin

Matthew Perry, Justin Bartha

Colin Farrell

Annette Bening, Cheryl Hines, Shawn Johnson & Derek Hough

Zac Efron, Rebel Wilson, Ed Sheeran

Eric Dane, Mike "The Situation" Sorrentino, Paul "Pauly D" DelVecchio, Ronnie Ortiz-Magro, Vinny Guadagnino, OneRepublic

Matchbox Twenty

Liam Neeson, Gilles Marini & Peta Murgatroyd, Cher Lloyd

Selena Gomez, Kobe Bryant, the Killers

Jennifer Garner, Dwight Howard

Joseph Gordon-Levitt, Kerry Washington, No Doubt

Zooey Deschanel, Maggie Elizabeth Jones, No Doubt

Bethenny Frankel, Viola Davis, Pamela Anderson

Dennis Quaid, Jenna Dewan-Tatum

Amy Poehler, Ricky Gervais

Michael J. Fox, L.A. Reid, PSY

Clint Eastwood, Pattie Mallette, Carly Rae Jepsen

Bethenny Frankel, Kellie Pickler, the top four from "So You Think You Can Dance"

Justin Bieber, Phillip Phillips

Katy Perry, Little Big Town

Dave Matthews Band, Allison Janney, Reese Witherspoon

Britney Spears, Simon Cowell

Pink, Patrick Dempsey, Gabrielle Douglas, McKayla Maroney, Kyla Ross

Vanessa Williams, Sarah Hyland

Vince Vaughn, Kat Graham, Bethenny Frankel

Ellie Kemper, Rufus Wainwright

Matt LeBlanc, Olivia Munn

Charlize Theron

Will Smith, Justin Bieber

Katy Perry, Alanis Morissette

Howie Mandel, Cat Deeley

Ellen's 1500th show

Russell Brand

Steve Carell, Brooklyn Decker, Bobby Brown

Jennifer Lopez, Cameron Diaz, John Mayer, Victoria Justice

Kate Beckinsale, Taylor Kitsch, "The Voice" winner Jermaine Paul

Hilary Duff, Nick Cannon, Molly Sims

Nicki Minaj

Carrie Underwood, Anna Kendrick

Johnny Depp, Chloe Grace Moretz, Michelle Pfeiffer, Alison Sweeney, Flo Rida

Eva Mendes, Beth Ostrosky Stern

Scarlett Johansson, Robert Downey Jr., "The Voice" castoff Jamar Rogers

Bill Clinton

Julianna Margulies, Kevin Nealon

Jessica Alba, Scott Caan, Paul "DJ Pauly D" DelVecchio

Diane Keaton, Donald Driver & Peta Murgatroyd

Hugh Grant

Adam Levine, Sophia Grace & Rosie, "American Idol" castoff Colton Dixon

Jack Black, Cobie Smulders

Jesse Tyler Ferguson, Rita Wilson, Cory Booker, Grace Potter & the Nocturnals

Sharon Osbourne, Maria Menounos & Derek Hough, Roberto Martin

Nicole Richie, Jennie Garth, Tom Shadyac

Wanda Sykes, Bon Iver

Mariska Hargitay, Squeeze, Megan Hilty

Emily Blunt, Jason Mraz

Michelle Obama, Katharine McPhee, Neon Trees

Sean Hayes, Gabrielle Union, Wayne Pacelle

Maya Rudolph, Josh Bowman, Karmin

Khloe Kardashian Odom, Ellie Goulding

Jane Lynch, Alison Sweeney, Bonnie Raitt

Cee-Lo Green, Miranda Kerr, Chloe & Halle Bailey

Jason Biggs, Colbie Caillat, Common

Jennifer Love Hewitt, Rascal Flatts, Kym Douglas

Emma Stone, Kenny Chesney, Tim McGraw, Time Salaz

Andrew Garfield, Edie Falco, Mo Isom

Colin Farrell, Seann William Scott, Lionel Richie

Julia Roberts, Liam Hemsworth, Justin Bieber, Carly Rae Jepsen

Kristin Chenoweth, K'Naan featuring Nelly Furtado

Elizabeth Banks, Casey James

Armie Hammer, Kevin Nealon, Birdy

Ed Helms, Kathy Freston

Amanda Peet

Ewan McGregor, Drew Brees, Toby Keith

Jonah Hill, Chris Rene

Jessica Simpson, Ellie Kemper, Dierks Bentley & the Punch Brothers

Jason Segel, Jennifer Morrison, Cirque du Soleil's Ants

David Arquette, Robin Thicke

Megan Fox, Carson Daly, Justin Willman

Jon Hamm, Michael Weatherly, Sara Bareilles

Christian Slater, Lenny Kravitz

Julianne Moore, Idina Menzel

Steve Harvey, Jason Mraz

Justin Bieber, Lauren Gray, Megan Mullally

Cheryl Hines, Kacie Boguskie, Steve Spangler

Kate Walsh

Meredith Vieira, Emily VanCamp

Seth Rogen, Bethenny Frankel

Jennifer Aniston, Cirque du Soleil's Juggling Ants

Randy Jackson, Justin Theroux, Natasha Bedingfield

Taylor Swift, Zac Efron

Amanda Seyfried

Reese Witherspoon, Nathan Lane

Sean "Diddy" Combs, 2012 Sports Illustrated Swimsuit cover model Kate Upton

Ellen Pompeo, Dierks Bentley

Kris Jenner, Bruce Jenner

Jennifer Lopez, Marc Anthony, Jamie King

Denzel Washington, Kat Dennings, LL Cool J

Channing Tatum

Julie Bowen, Josh Hutcherson, the Band Perry

Martin Scorsese, Rachel McAdams

Jim Parsons, Miley Cyrus

Christina Aguilera, Adam Levine, Blake Shelton

Michelle Obama, Daniel Radcliffe

Drew Barrymore, Octavia Spencer, Flo Rida

Simon Baker, Kristen Bell

John Krasinski, 2Cellos

Ted Danson, Kellie Pickler, Christopher Plummer

Jimmy Kimmel, Melissa McCarthy, Earth Wind & Fire

Mario Lopez, Ben Flajnik

Sam Worthington, Michael Strahan, Seal

Shemar Moore, Kym Douglas

Kiefer Sutherland, Kevin Nealon

Rob Lowe, Adam Lambert

Colin Firth, Jeremy Irvine, Uggie the dog, Colbie Caillat

Steven Tyler, Timothy Oliphant, Chris Young

Sofia Vergara, Big Time Rush

Queen Latifah, Kenneth Branagh

Meryl Streep, Ricky Gervais, Snow Patrol

James Spader, Jeremy Irvine, Daniel J. Simons & Jonah Richard Lehrer

Woody Harrelson, Joshua Jackson, the Wanted

Kelly Osbourne, Shervin Lalezary, Nolan Gould, Gavin DeGraw

Kirstie Alley, Jordyn Wieber

Jersey Shore Cast

Timothy Olyphant, Sarah Hyland, Justin Flom

Dennis Quaid, Justin Bieber, Mindless Behavior

Alison Sweeney, Allen Stone

Howie Mandel, Elle Fanning