10x1 - Christina Ricci, Mike 'The Situation' Sorrentino, Paul 'DJ Pauly D' DelVecchio, Vinny Guadagnino, Ronnie Ortiz-Magro, Mariachi El Bronx

January 3, 2012

10x2 - Kelsey Grammer, Octavia Spencer, Lloyd

January 4, 2012

10x3 - Tracy Morgan, Chris Paul, tUnE-yArDs

January 5, 2012

10x4 - Don Cheadle, David Cross, Boyz II Men

January 6, 2012

10x5 - Channing Tatum, Ben Flajnik, Uh Huh Her

January 9, 2012

10x6 - Randy Jackson, Dermot Mulroney, Will Hoge

January 10, 2012

10x7 - Woody Harrelson, Yvonne Strahovski, Rodney Atkins

January 11, 2012

10x8 - Meryl Streep, Stephen Merchant, Kina Grannis

January 12, 2012

10x9 - Katherine Heigl, Ne-Yo, Grouplove

January 17, 2012

10x10 - Will Arnett, Madeleine Stowe, Dana Gould

January 18, 2012

10x11 - Tom Arnold, Keke Palmer, Filter

January 19, 2012

10x12 - Terrence Howard, Thomas Horn, Safetysuit

January 20, 2012

10x13 - Kiefer Sutherland, Bear Grylls, Young the Giant

January 23, 2012

10x14 - Elizabeth Banks, Ben McKenzie, Mindless Behavior

January 24, 2012

10x15 - Cuba Gooding Jr., Sara Hyland, Big Freedia

January 25, 2012

10x16 - Andre Agassi, J.B. Smoove, Seal

January 26, 2012

10x17 - Kate Walsh, Marc Maron, Fishbone

January 30, 2012

10x19 - John Krasinski, Eloise Mumford, Gotye

February 1, 2012

Director Martin Scorsese ("Hugo"); Kenneth Branagh ("My Week With Marilyn"). Also: Angels & Airwaves perform.

10x20 - Gary Oldman, Tim Heidecker & Eric Wareheim, Korn

February 2, 2012

10x21 - Michelle Williams, Angela 'Big Ang' Raiola, Pitbull

February 6, 2012

10x22 - Antonio Banderas, Damon Wayans Jr., 50 Cent

February 7, 2012

10x23 - Nathan Fillion, Josh Hutcherson, Far East Movement

February 8, 2012

10x24 - Courteney Cox, Mario Manningham & Ahmad Bradshaw, Tony Bennett

February 9, 2012

10x25 - Jeff Goldblum, David Alan Grier, Lana Del Rey

February 13, 2012

10x26 - John Goodman, Kevin Nealon, Robin Thicke

February 14, 2012

10x27 - Sean 'Diddy' Combs, 'Science Bob' Pflugfelder, Miley Cyrus

February 15, 2012

10x28 - Chris Pine, Khloe Kardashian Odom, Puscifer

February 16, 2012

10x29 - Eric Stonestreet, Kate Upton, Jake Owen

February 21, 2012

10x30 - Jessica Alba, Rep. Barney Frank, Nathan Myhrvold, Tower of Power

February 22, 2012

10x31 - Joel McHale, Justin Theroux, Die Antwoord

February 23, 2012

10x32 - After the Oscars Special

February 26, 2012

Oprah Winfrey; Musical Guest Coldplay

10x33 - Steven Tyler, Harvey Weinstein, Melanie Fiona

February 27, 2012

10x34 - Maria Menounos; Mat Kearney

February 28, 2012

“Dancing with the Stars” contestant Maria Menounos; musical guest Mat Kearney.

10x35 - Ed Helms, Leslie Bibb, Wallpaper

February 29, 2012

10x36 - Joan Rivers, Nicki Minaj

March 1, 2012

10x37 - Dr. Phil McGraw; “The Bachelor” runner-up Lindzi Cox; Keane

March 12, 2012

10x38 - Will Ferrell; actress Ellie Kemper; Allen Stone

March 13, 2012

Actor/comedian Will Ferrell; actress Ellie Kemper; music from Allen Stone.

10x39 - Jonah Hill; Busy Philipps; The Crystal Method feat. Martha Reeves

March 14, 2012

10x40 - Channing Tatum; actor Genesis Rodriguez

March 15, 2012

Actor Channing Tatum; actress Genesis Rodriguez.

10x41 - Jessica Simpson; Gael García Bernal

March 19, 2012

Actress Jessica Simpson; actor Gael García Bernal.

10x42 - Kristen Bell; actor Ice Cube; KISS performs

March 20, 2012

Actress Kristen Bell; actor/musician Ice Cube; musical guests KISS.

10x43 - Don Rickles; Amanda de Cadenet; Dr. Teeth and the Electric Mayhem

March 21, 2012

10x44 - Kristin Chenoweth; racecar driver Jimmie Johnson; Neon Trees

March 22, 2012

10x45 - Zooey Deschanel; actor Steven Seagal; Shinedown

March 26, 2012

Actress Zooey Deschanel; actor Steven Seagal; musical guests Shinedown.

10x46 - Ashton Kutcher and Justin Bieber; All-American Rejects

March 27, 2012

10x47 - Adam Carolla; professional basketball player Kevin Durant; White Rabbits

March 28, 2012

10x48 - Carson Daly; actress Kristen Schaal

March 29, 2012

10x49 - Seann William Scott; actress Christa Miller; Eli Young Band

April 2, 2012

10x50 - Edie Falco; Amy Schumer

April 3, 2012

10x51 - Jason Biggs; Lionel Richie and Billy Currington

April 4, 2012

10x52 - Anthony Davis; actress Lena Headey; NeedToBreathe

April 5, 2012

10x53 - LL Cool J; actor James Van Der Beek; Josh Baze

April 9, 2012

10x54 - David Spade; Slash feat. Myles Kennedy

April 10, 2012

10x55 - Ashley Judd; director Bobcat Goldthwait; The Civil Wars

April 11, 2012

10x56 - Danny McBride; actress Dianna Agron; The Shins

April 12, 2012

10x57 - Zac Efron; actress Krysten Ritter; Noel Gallagher

April 16, 2012

10x58 - Mark Harmon; Dancing With the Stars castoff; Ashanti performs

April 17, 2012

10x59 - Jennifer Love Hewitt; Chef Georgia Pellegrini; Jason Mraz

April 18, 2012

10x60 - Gabourey Sidibe; Morgan Spurlock; Kasabian

April 19, 2012

10x61 - Julia Louis-Dreyfus; Andy Hoang & Erik Salgado; The Hives

April 23, 2012

Actress Julia Louis-Dreyfus; Scrabble champions Andy Hoang & Erik Salgado; musical guests The Hives.

10x62 - John Cusack; Vintage Trouble

April 24, 2012

10x63 - Sharon Osbourne; Max Greenfield; LP

April 25, 2012

10x64 - Emily Blunt; Dave Salmoni; Adam Lambert

April 26, 2012

10x65 - Vanessa Williams; Jonny Lee Miller; Andrew Bird

April 30, 2012

10x66 - David Arquette; Civil Twilight

May 1, 2012

10x67 - William H. Macy; Eva Green; Brad

May 2, 2012

10x68 - Scarlett Johansson; Roger Daltrey

May 3, 2012