Actor Gerard Butler (Bounty Hunter), actress Gabrielle Union (FlashForward), musical guest Jamie Cullum.

Actor David Arquette (The Female of the Species), actress Abbie Cornish (Bright Star), stand up comedian Jim Breuer

Actor Neil Patrick Harris (How I Met Your Mother), actor Jeremy Renner (The Hurt Locker), musical guest Really Doe.

Actress Ellen Pompeo (Grey's Anatomy), NFL analyst Michael Strahan (Brothers, "NFL Sunday"), musical guest Puddle of Mudd

Actor Tobey Maguire (Brothers), actress Shenae Grimes (90210), musical guest Colbie Caillat performs "I Never Told You"

Jimmy as "Jay Leno" hosts. Actor Chevy Chase (Community), actress Elisha Cuthbert (The Forgotten and 24), musical guest Melanie Fiona performs "It Kills Me"

Jimmy spoke with actress Kate Walsh (Legion and Private Practice) about turtles and speaking Spanish, and actor Aziz Ansari (Aziz Ansari: Intimate Moments for a Sensual Evening and Parks and Rec) about his breakthrough year on television and his fascination with R. Kelly. Also, musical guests Larry Gatlin and the Gatlin Brothers performed "Johnny Cash is Dead." But first, Jimmy says goodbye to Michael Jackson's giraffes, J.J. and Rambo, who died, and we get a special peek into Guillermo's scandal on The Bachelor.

Actress Evangeline Lilly (Lost), Miss South Carolina Teen USA 2007 Caite Upton, musical guest Katharine McPhee

Actor Dax Shepard (When in Rome), personality Joan Rivers, chef Paul Bartolotta

Actor Dennis Quaid (Legion), actor Ty Burrell (Modern Family), musical guest Orianthi

Actor Paul Bettany (Legion), The Bachelor Jake Pavelka, musical guest Pearl

Actor Dwayne Johnson (Tooth Fairy), Duane "Dog" Chapman (Dog the Bounty Hunter), stand-up comedian Dwayne Kennedy

Actress Cheryl Hines (Brothers & Sisters), actor Jared Harris (Extraordinary Measures), musical guest Heartless Bastards

Actor Harrison Ford (Extraordinary Measures), actress Kristin Bell (When in Rome), musical guest Silversun Pickups

Actor Mel Gibson (Edge of Darkness), actress Kate Micucci (When in Rome), musical guest Mayer Hawthorne

Actor Will Arnett (When in Rome), actress Kim Raver (Grey's Anatomy), musical guest Slightly Stoopid

Jimmy spoke with actor Josh Duhamel (When in Rome) about doing his own stunts, and Shorty Rossi (Animal Planet's Pit Boss) about his pit bulls and dating tall women. And musical guest John Mayer performed "Heartbreak Warfare." But first, Jimmy led the audience in pledging their lives to Oprah for her birthday, and Guillermo broke the news to Jimmy about a nationwide salami recall. Also, it's Friday, which meant another installment of This Week in Unnecessary Censorship

Tennis champion Serena Williams, Damon Lindelof and Carlton Cuse (writers of Lost), musical guest Lady Antebellum

Jimmy interviewed Dr. Phil McGraw (Dr. Phil) and musician Nick Jonas (Nick Jonas and the Administration), and stand-up comedian Demetri Martin performed.

Jimmy spoke with actor Eric Dane (Valentine's Day and Grey's Anatomy) and celebrity Kourtney Kardashian. Musical guest The Bravery performed "Hateful." But first, Jimmy's natural comedic ability in working with children shined as he dressed as a pig and talked to two young boys. After having a brief chat on how hard it is to be a fat pig, Jimmy convinced the boys to give him water even though they were told not to. Jimmy then peed all over Cowboy Cousin Sal.

Jimmy interviews Ozzy Osbourne (I Am Ozzy) and Barry Manilow; Barry Manilow performs

Oscar nominee Maggie Gyllenhaal (Crazy Heart), animal specialist Dave Salmoni, musical guest Ryan Bingham

Actress Emily Blunt (The Wolfman), actor J.B. Smoove (Curb Your Enthusiasm), musical guest Editors

Actor Patrick Dempsey (Valentine's Day and Grey's Anatomy), actress Lake Bell (How to Make it in America), stand-up comedian Greg Giraldo (Midlife Vices)

Actor Mark Wahlberg (How to Make it in America), Sports Illustrated Swimsuit Issue cover model Brooklyn Decker, musical guest Dashboard Confessional