Kristen Bell

Emmy Rossum

Robin Wright

RZA

Laura Prepon

Kaley Cuoco

Kristin Chenoweth

Pauly 'DJ Pauly D' DelVecchio

Bill Maher

Giovanni Ribisi

Kim Wayans

Amy Brenneman

Kate Beckinsale

Alexa Chung with guest host Ross Mathews

Dot-Marie Jones with guest host Ross Mathews

Lisa VanderPump wth guest host Ross Mathews

The Meatball Shop Guys with guest host Ross Mathews

Wanda Sykes

Jenny McCarthy & Sabra Ricci

Don Cheadle

Kristen Bell

Piers Morgan

Kelly Rowland

The Wanted

LeeAnn Rimes

Christa Miller

Stella Starsky & Quinn Cox

Reese Witherspoon

Lenny Kravitz

Amanda Seyfried

Jennifer Aniston

Gabourey Sidebe

Tyler Perry

Maria Sharapova

Ellen Pompeo

Dr. Mehmet Oz

Jake Owen

Idina Menzel

Geoff Stults

Julianne Moore

Jennifer Westfeldt

Stanley Tucci

Josh Gad

Leslie Bibb

Shirley Manson

Jonah Hill & Channing Tatum

Adrien Brody

Nicole Richie

Jennifer Lawrence

Mena Suvari

Toby Keith

Bethenny Frankel

Chris Klein

Kathy Najimy

Guy Pearce

Chris Colfer

Shannen Doherty

Kelly Lynch

Lena Dunham

Gabrielle Union

Lauren Conrad

Jason Mraz

Ricki Lake

Alison Brie

Mary McCormack

Kathy Griffin

Raphael Saadiq

Jennifer Love Hewitt

James Van Der Beek

Morgan Spurlock

Ian Somerhalder

Adam Lambert

Craig Ferguson

Cameron Diaz

Brooklyn Decker

Giada De Laurentiis

Randy Jackson

Dina Eastwood

Donald Schultz

Malin Akerman

Bar Refaeli

David Hasselhoff

Karmin

Tamra Barney & Gretchen Rossi

Mary J. Blige

LMFAO

Aubrey Plaza

Charlize Theron

Gabriel Macht

Giovanni Ribisi

Nelsan Ellis

Ellen Page

Kevin Nealon

Cat Cora

Kylie Minogue

Zach Wahls

Erin Wasson

Oliver Stone

Joe Manganiello

Pete Wentz & Jason Derulo

Meghan McCain

Russell Brand

Josh Henderson

Jenny McCarthy

Gustavo Arellano

Lionel Richie

Kathy Najimy

Callie Thorne

Roy Handler

Carla Gugino

Rick Ross

Mike Epps

Joy Bryant

Michael Ealy

Jeff Daniels

Kate Beckinsale

Blake Shelton

Will Ferrell

Wiz Khalifa

Norah Jones

Matt LeBlanc

Kevin Jonas

Bridget Mary McCormack

Hope Solo

Lisa Kudrow

Isla Fisher

Kirsten Dunst

Alanis Morissette

Shia LaBeouf

Lizzy Caplan

Guy Pearce

Zoe Saldana

Sanya Richards-Ross

Abby Lee Miller

Nina Dobrev

Kate Walsh

Tim Gunn

Milla Jovovich

Jennifer Garner

Eva Longoria

Melissa Etheridge

Alyson Hannigan

Carly Rae Jepsen

Wyclef Jean

Penny Marshall

Kristin Chenoweth

Paul 'Pauly D' DelVecchio

Victoria Justice

Jennifer Garner

Jenny McCarthy

Diego Boneta

Sam Rockwell

Bryan Cranston

Jennifer Aniston

Fergie

Miley Cyrus

Christina Aguilera

Tyler Perry

Zachary Quinto

Helen Hunt

Chuck Lorre

Halle Berry

Kerry Washington

John C. Reilly

Jane Lynch

Ellen Barkin

Chef Roy Handler

Gina Gershon

Hayden Panettiere

Martha Plimpton

Chelsea Lately Dance Crew

Nate Berkus

Ne-Yo

Rascal Flatts

Pitbull

Max Greenfield

Ginnifer Goodwin

Marion Cotillard

Whitney Cummings

Alessandra Ambrosio

Blake Shelton

Adrien Brody

Dwight Yoakam

Adam Pally

Ray Romano

Gerard Butler

Jessica Chastain

Adam Levine

Amanda Seyfried

Anne Hathaway

Drew Barrymore

Kevin Pollak

Judd Apatow

Marisa Tomei

Reese Witherspoon

Dita Von Teese