S20 E1: Whitney Cummings, Nicole

S20 E2: Tracy Morgan, Rick & Corey Harrison, Shaggy

S20 E3: Michelle Williams, Josh Lucas, Chris Cornell

S20 E4: Glenn Close, Trevor Noah, Van Hunt

S20 E5: Janet Jackson, Larry the Cable Guy, Eli Young Band

S20 E6: Queen Latifah, Paul

S20 E7: Liam Neeson, Jack's Mannequin

S20 E8: Gerard Butler, Betty White

S20 E9: Tilda Swinton, Jennifer Hudson, Graffiti6

S20 E10: Sam Worthington, Sherri Shepherd, Adam Lambert

S20 E11: Jennifer Garner, Ross Matthews, Parachute

S20 E12: Wanda Sykes

S20 E13: Steven Tyler, Ryan Seacrest, Randy Jackson, Sarah Colonna

S20 E14: Madonna, Chris Colfer, Joe Perry

S20 E15: Michelle Obama, Mark Harmon, Imelda May

S20 E16: Daniel Radcliffe, Vanessa Hudgens, Evanescence

S20 E17: Drew Barrymore, Blake Shelton

S20 E18: Debra Messing, Jean Dujardin, Bush

S20 E19: Dwayne Johnson, Miranda Cosgrove, Cirque du Soleil

S20 E20: Chelsea Handler, Jon Huntsman, 2Cellos

S20 E21: Chris Pine, Lisa Lampanelli, Anthony Hamilton

S20 E22: Denzel Washington, Octavia Spencer, Estelle

S20 E23: Rachel McAdams, Cee-Lo Green

S20 E24: Jennifer Lopez, the Civil Wars

S20 E25: Tyler Perry, Alexandra Wentworth, the Cranberries

S20 E26: Bill Maher, Punch Brothers

S20 E27: Amanda Seyfried, Billy Gardell, Monica, Brandy

S20 E28: Christina Aguilera, Dave Salmoni, The Fray

S20 E29: Taylor Swift, Michael Clarke Duncan, Robert Randolph, Los Lobos, Chris Layton

S20 E30: Bill O'Reilly, Rob Riggle, Rumer

S20 E31: Tim Allen, Rocket City Rednecks

S20 E32: Meredith Vieira, Jackson Murphy

S20 E33: Jennifer Aniston, Adam Levine

S20 E34: Megan Fox, Michel Hazanavicius, Mariachi El Bronx

S20 E35: Rob Schneider, Khloe Kardashian Odom, Mona

S20 E36: Sen. John McCain, Elizabeth Olsen, Romeo Santos

S20 E37: Julianne Moore, Dr. Brady Barr, Chickenfoot

S20 E38: Emily Blunt, Geoff Stults, Scars on 45

S20 E39: Jessica Simpson, Adam Carolla, Soja

S20 E40: Jonah Hill, Bethenny Frankel, Shooter Jennings

S20 E41: Channing Tatum, Drew Brees, Meat Loaf

S20 E42: Kiefer Sutherland, Kathryn Hahn, Andy Grammer

S20 E43: Jimmy Fallon, 8-year-old presidential whiz kid H.L. McCullough, Toby Keith

S20 E44: Jamie Lee Curtis, Armie Hammer

S20 E45: Rep. Ron Paul, Frank Caliendo, the Wanted

S20 E46: Kim Kardashian

S20 E47: Arsenio Hall, Lily Collins

S20 E48: Christina Aguilera, Melanie Fiona featuring J. Cole

S20 E49: Elizabeth Banks, Carson Daly

S20 E50: The Pierces

S20 E51: Rainn Wilson, Debbie Gibson, Gavin DeGraw

S20 E52: Piers Morgan, Liam Hemsworth, Mat Kearney

S20 E53: Nicole Richie, Alan Jackson

S20 E54: Betty White, D.J. Pauly D

S20 E55: Maya Rudolph, Jason Biggs, Gym Class Heroes

S20 E56: David Gregory, Cee-Lo Green, Seal

S20 E57: Zac Efron, Jennie Garth, Grace Potter and the Nocturnals

S20 E58: Kristin Chenoweth, Julie Scardina, Rodrigo y Gabriela

S20 E59: Jane Lynch, Kevin Hart, Esperanza Spalding

S20 E60: Josh Hutcherson, Rachel Maddow, Eric Turner featuring Lupe Fiasco and Tinie Tempah

S20 E61: Albert Brooks, Austin

S20 E62: Blake Shelton, Chris Diamantopoulos, Feist

S20 E63: Jason Segel, Anna Faris, Far East Movement

S20 E64: Jesse Tyler Ferguson, Aubrey O'Day, Train

S20 E65: Jack Black, Daniel Holzman & Michael Chernow, Beirut

S20 E66: Adam Levine, Ziggy Marley

S20 E67: Diane Keaton, Natalie Coughlin, Moby

S20 E68: Mel Gibson, the Wanted

S20 E69: Steve Martin, Rashida Jones, Steve Martin & the Steep Canyon Rangers

S20 E70: Cameron Diaz, William Shatner, Lee Brice

S20 E71: Scarlett Johansson, Blake Shelton, K'Naan featuring Nelly Furtado

S20 E72: Robert Downey Jr., Katharine McPhee, Toast To Freedom

S20 E73: Kristen Stewart, James Morrison

S20 E74: Michelle Pfeiffer, Bear Grylls, Snow Patrol

S20 E75: Rick Santorum, Taylor Kitsch, B.o.B., O.A.R.

S20 E76: Garry Shandling, Alison Brie, the winner of 'The Voice'

S20 E77: Howie Mandel, Vinny Guadagnino, Sara Watkins

S20 E78: Jenna Fischer, Jay Mohr

S20 E79: Kourtney, Kim & Khloe Kardashian, Donny Deutsch, Karmin

S20 E80: Wanda Sykes, David Hasselhoff, Santana

S20 E81: Joel McHale, Jarod Miller, Bobby Brown

S20 E82: Hugh Laurie, Robert Griffin III

S20 E83: Sherri Shepherd, Julianne Hough, Tenacious D

S20 E84: Kevin Costner, Bailee Madison, Lisa Marie Presley

S20 E85: Josh Brolin, Ali Wentworth, Glenn Frey

S20 E86: Charlize Theron, Jeffrey Dean Morgan, Juanes

S20 E87: Glenn Close, the winner of American Idol, Nelly Furtado

S20 E88: Gen. Colin Powell, Greg Gadson, All American Rejects

S20 E89: Martin Short, Aubrey Plaza, Def Leppard

S20 E90: Emma Stone, Chris Hemsworth, Chris Robinson Brotherhood

S20 E91: Julia Louis-Dreyfus, the Beach Boys

S20 E92: Catherine Zeta-Jones, Louis Zamperini, Bret Michaels

S20 E93: Tom Cruise, skydivers Felix Baumgartner & Joe Kittinger, Kool & the Gang

S20 E94: Elizabeth Banks, Dan Patrick, Brandi Carlisle

S20 E95: Patrick Duffy, Linda Grey, Larry Hagman, Meghan McCain, Meiko

S20 E96: Terry Bradshaw, Ernie Brown Jr., Neal James, Rachel Bradshaw

S20 E97: Penelope Cruz, Rick Harrison, We Are Augustines

S20 E98: Salma Hayek, Adam Brody, Olly Murs

S20 E99: Steve Carell, Cory Booker, Glen Hansard

S20 E100: Matthew McConaughey, Natasha Leggero, Grouplove

S20 E101: Andy Samberg, Seth MacFarlane, Joe Henry featuring Lisa Hannigan

S20 E102: Katy Perry, Needtobreathe

S20 E103: Chris Pine, Rachael Ray, Everclear

S20 E104: Louis C.K., Lolo Jones, Delta Rae

S20 E105: Matt LeBlanc, Sig Hansen & Keith Colburn, Robin Thicke

S20 E106: Mila Kunis, Jim Norton, Justin Bieber

S20 E107: Tyler Perry, Rhys Ifans, Keane

S20 E108: Andrew Garfield, Of Monsters And Men

S20 E109: Wanda Sykes, Rob Riggle, Kimbra

S20 E110: Zachary Levi, B.o.B.

S20 E111: Morgan Freeman,

S20 E112: Denis Leary, Olivia Munn, Kenny Chesney

S20 E113: Dana Carvey, Nicki Minaj

S20 E114: Charlie Sheen

S20 E115: Kate Beckinsale, Adam Carolla

S20 E116: Newt Gingrich, Nicole

S20 E117: Rachel Weisz, Aaron Paul

S20 E118: Ben Stiller, Rose Byrne, Missy Higgins

S20 E119: Vince Vaughn, Travis Pastrana, Aretha Franklin

S20 E120: Colin Farrell, Jenni

S20 E121: Jessica Biel, Kevin Smith, the Lumineers

S20 E122: Julie Scardina, Dwyane Wade, MoZella

S20 E123: Jeremy Renner, Betty White, Joss Stone

S20 E124: Michelle Obama, Norah Jones

S20 E125: Kelsey Grammer, Jordan Burroughs, Ryan Star

S20 E126: Sylvester Stallone, Missy Franklin, Dwight Yoakam

S20 E127: Kristen Bell, Ryan Lochte, Regina Spektor

S20 E128: Jason Statham, Allyson Felix, the Offspring

S20 E129: Maya Rudolph, Jeff Foxworthy, Morning Parade

S20 E130: Shia LaBeouf, Jean-Claude Van Damme, fun.

S20 E131: Katie Couric, Dax Shepard, Emeli Sande

S20 E132: Kirsten Dunst, Chris Matthews, Smashing Pumpkins

S20 E133: Howie Mandel, Alejandro Escovedo

S20 E134: Dennis Miller, Joshua Radin

S20 E135: Owl City with Carly Rae Jepsen

S20 E136: Bill Maher, Tristan Prettyman

S20 E137: Savannah Guthrie, Dolph Lundgren

S20 E138: Lauren Graham, Dan Patrick

S20 E139: Kevin Hart, Rep. Ron Paul, Robert Cray

S20 E140: Adam Levine, Magic Johnson, Grace Potter

S20 E141: Ellen DeGeneres, Josh Lucas, Billy Ray Cyrus

S20 E142: Matthew Perry, Meghan McCain, OneRepublic

S20 E143: Richard Gere, Anthony Robles, Rascal Flatts

S20 E144: Justin Timberlake, Steve Nash, Ryan Bingham

S20 E145: Amy Poehler, Joe Scarborough, Big & Rich

S20 E146: Viola Davis, Paul Wesley, Bonnie Raitt

S20 E147: Zooey Deschanel, Anthony Anderson, ZZ Top

S20 E148: David Spade, Giancarlo Esposito, Rebecca Ferguson

S20 E149: Ann Romney, Seth MacFarlane, Bettye LaVette

S20 E150: Kirstie Alley, Mike

S20 E151: Liam Neeson, Lisa Lampanelli, the Gaslight Anthem

S20 E152: Christina Aguilera, Sherri Shepherd, the Piano Guys

S20 E153: Bryan Cranston, Rebel Wilson, Cher Lloyd

S20 E154: Carol Burnett, Armie Hammer, Lang Lang

S20 E155: Christina Applegate, Apolo Anton Ohno

S20 E156: Ben Affleck, Octavia Spencer, Neon Trees

S20 E157: Colin Farrell, Medal of Honor recipient Dakota Meyer, the Hives

S20 E158: Arnold Schwarzenegger, Bubba Watson, the Wallflowers

S20 E159: Tyler Perry, Oscar Pistorius, Plain White T's

S20 E160: Chelsea Handler, Placido Domingo

S20 E161: Terry Bradshaw, Mark Kelly, Grizzly Bear

S20 E162: Whitney Cummings, Rove McManus, the Script

S20 E163: Halle Berry, Ali Wentworth, Gary Clark Jr.

S20 E164: Denzel Washington, Richard Engel, M. Ward

S20 E165: President Barack Obama, No Doubt

S20 E166: Russell Brand, Jane Lynch

S20 E167: Sarah Silverman, Paula Deen

S20 E168: Simon Cowell, Britney Spears, Billy Gardell, Two Door Cinema Club

S20 E169: John C. Reilly, Jenni

S20 E170: Taylor Lautner, Lior Suchard, Macy Gray

S20 E171: Jamie Lee Curtis, Maggie Elizabeth Jones, ZZ Ward

S20 E172: Marion Cotillard, Olate Dogs

S20 E173: Kristen Stewart, Dax Shepard, Kip Moore

S20 E174: Daniel Craig, Dave Salmoni, Diamond Rings

S20 E175: Sally Field, Chris Matthews, Lord Huron

S20 E176: Meredith Vieira & Richard Cohen, Christina Perri

S20 E177: Lea Michele, Nev Schulman, Toby Keith

S20 E178: Keira Knightley, Whitney Cummings, Gin Wigmore

S20 E179: Helen Hunt, Paul

S20 E180: Tim Allen, Nolan Gould, Switchfoot

S20 E181: Chris Matthews, the Mowgli's

S20 E182: Jennifer Lawrence, Phil & Willie Robertson, Andy Grammer

S20 E183: Lindsay Lohan, David Gregory, Wanda Jackson

S20 E184: Joseph Gordon-Levitt, Kris Jenner, Dan Cummings

S20 E185: Bradley Cooper, Natasha Leggero, PSY

S20 E186: Jim Parsons, Maggie Elizabeth Jones, Delta Rae

S20 E187: Julie Bowen,

S20 E188: Wanda Sykes, Blake Shelton

S20 E189: Newt Gingrich, Ron Shirley, Grouplove

S20 E190: Marisa Tomei, Carson Daly, Il Volo

S20 E191: Gerard Butler, Olivia Munn, the Polyphonic Spree

S20 E192: Khloe Kardashian Odom, Adam Carolla, Matisyahu

S20 E193: Don Johnson, Julie Scardina, Darius Rucker

S20 E194: Bill O'Reilly, Krysten Ritter, Paloma Faith

S20 E195: Leslie Mann, Jim Rome, Garbage

S20 E196: Matt Damon, Chris Pratt, Of Monsters And Men

S20 E197: Ewan McGregor, Bailee Madison, Allen Stone

S20 E198: Albert Brooks, Kerry Washington, Willy Moon

S20 E199: Hugh Jackman, Maria Sharapova, J.D. McPherson

S20 E200: Bette Midler, Judd Apatow, Pentatonix

S20 E201: Megan Fox, Johnny Manziel, Colbie Caillat

S20 E202: Quentin Tarantino, LeAnn Rimes

S20 E203: Jamie Foxx, Carl Reiner, the winner of

S20 E204: Katherine Heigl, Marjorie Johnson, Johnny Mathis

S20 E205: Terry Bradshaw, Elle Fanning, Chris Mann