S18E01 - Brian Williams, Paula Abdul

S18E02 - Tim McGraw, Shaquille O'Neal, Keri Hilson

S18E03 - Jennifer Connelly, Dr. Oz, Justin Townes Earle

S18E04 - Seth Rogen, Beau Garrett, the Walkmen

S18E05 - Regis Philbin, Hannibal Buress, No Age

S18E06 - Bill Cosby, a Top Ten List presented by Nicole "Snooki" Polizzi, the Black Keys

S18E07 - Vince Vaughn, Mike Wolfe & Frank Fritz, Cage the Elephant

S18E08 - Kevin James, Olivia Munn, The Low Anthem

S18E09 - Kelsey Grammer, Amar'e Stoudemire, Gregg Allman

S18E10 - Joan Rivers, Jeff Caldwell, Wintersleep

S18E11 - Jack Hanna, Steven Tyler

S18E12 - Betty White, Kim & Kourtney Kardashian, the Script

S18E13 - Martin Short, Greta Gerwig, Darius Rucker

S18E14 - Kaley Cuoco, Piers Morgan, Wanda Jackson, Miss Arkansas, Alyse Eady

S18E15 - Nathan Lane, Mike Palascak, Esperanza Spalding

S18E16 - Justin Bieber, Pauley Perrette, Best Coast

S18E17 - Matthew Perry, Chris Elliott, Top Ten with Mitt Romney, the National

S18E18 - Kate Walsh, Jim Gaffigan, Boxer Rebellion

S18E19 - Howard Stern, Naughty By Nature

S18E20 - Martha Stewart, Top Ten with Justin Bieber, Robert Plant

S18E21 - Super Bowl MVP Aaron Rodgers, Martin Lawrence, Steel Magnolia

S18E22 - Adam Sandler, Chris Colfer, Gang of Four

S18E23 - Anderson Cooper, Elton John

S18E24 - Nicole "Snooki" Polizzi, Judah Friedlander, Bryan Ferry

S18E25 - Ed Helms, Ted Alexandro, Steel Magnolia

S18E26 - S.I. Swimsuit Cover Reveal & Top 10, Tom Brokaw, Theophilus London

S18E27 - Forest Whitaker, S.I. Swimsuit Cover Model Irina, Josh Groban, Top Ten with Joy Philbin

S18E28 - Bill Hader, Grocery Bagging Champ Krystal, Amos Lee

S18E29 - Paris Hilton, Nathan Fillion, Scissor Sisters

S18E30 - David Spade, Andy Kindler, Lukas Nelson and Promise of the Real

S18E31 - Donald Rumsfeld, Cobie Smulders

S18E32 - Amy Poehler, Jean Chu and Dusty the Cat, Deerhunter

S18E33 - Rainn Wilson, Hank Aaron

S18E34 - Senator Rand Paul, Bright Eyes

S18E35 - Matthew Morrison, Jeff Altman, Jessica Lea Mayfield

S18E36 - Brian Williams, Trey Parker & Matt Stone, Zac Brown Band

S18E37 - Amanda Seyfried, B.J. Novak

S18E38 - Donald Trump, Vanessa Hudgens, Oh Land

S18E39 - Robin Williams, Judy Greer

S18E40 - Charles Barkley, Sarah Vowell, Cold War Kids

S18E41 - Bradley Cooper, Mindy Kaling, Bob Geldof

S18E42 - Steve Martin, Selena Gomez

S18E43 - Dana Carvey, Dr. Michio Kaku, British Sea Power

S18E44 - Katie Couric, The Pains of Being Pure at Heart

S18E45 - Ben Stiller, Dario Franchitti, The Strokes

S18E46 - "Jungle" Jack Hanna, Danny McBride

S18E47 - Regis Philbin, Snoop Dogg

S18E48 - Norm Macdonald, CC Sabathia, Willie Nelson, Norah Jones and Wynton Marsalis

S18E49 - Chris Rock, Ellen Page, Funeral Party

S18E50 - James Franco, Royal Bangs

S18E51 - Jennifer Garner, Jamie Oliver, Robbie Robertson

S18E52 - Don Rickles, Eva Longoria

S18E53 - Alec Baldwin, Wiz Khalifa

S18E54 - Ricky Gervais, Top Ten with Katie Holmes, Foo Fighters

S18E55 - Courteney Cox, Aziz Ansari, Alison Krauss & Union Station featuring Jerry Douglas

S18E56 - Seth Meyers, Carmelo Anthony, TV on the Radio

S18E57 - Tina Fey, Tommy Johnagin, The Gaslight Anthem

S18E58 - Bill Maher, Cote de Pablo, Lupe Fiasco

S18E59 - Will Ferrell, The Twilight Singers

S18E60 - Kate Hudson, Rich Eisen, Emmylou Harris

S18E61 - Dr. Phil McGraw, Chris Hemsworth, Broadway musical "Catch Me If You Can"

S18E62 - John Krasinski, Brian Kiley, Steve Earle

S18E63 - Brian Williams, Rex Ryan

S18E64 - Caroline Kennedy, Ty Burrell

S18E65 - Betty White, Rick Harrison, Morning Teleportation

S18E66 - Jodie Foster, Tom Dreesen, Neon Trees

S18E67 - Bill Murray, ''The Human Fuse'' Brian Miser, Brother

S18E68 - Albert Brooks, Kristen Wiig

S18E69 - Mark Harmon, Chris Morgan, Hugo

S18E71 - Stupid human tricks, Jim Parsons, Manchester Orchestra

S18E72 - Joan Rivers, Nick Griffin, Okkervil River

S18E73 - Julianna Margulies, Andy Cohen, a Top Ten List presented by Christina Aguilera, White Lies

S18E74 - Martin Short, Melissa McCarthy, Tinie Tempah

S18E75 - Keith Olbermann, Julie Bowen, Ben Harper

S18E76 - Kelly Ripa, Jennifer Lawrence, How to Succeed in Business Without Really Trying

S18E77 - Tracy Morgan, Jake Johannsen, The Airborne Toxic Event

S18E78 - Lady Gaga, Eric Stonestreet, The Vaccines

S18E79 - Ewan McGregor, Scott Pelley, Brad Paisley

S18E80 - Piedmont Bird Callers, Kevin Bacon, Augustana

S18E81 - Ray Romano, Reese Waters, Arctic Monkeys

S18E82 - Meredith Vieira, Indianapolis 500 winner Dan Wheldon, Drum Solo Week kicks off with Anton Fig

S18E83 - Kyle Chandler, Kathy Griffin, Sheila E.

S18E84 - Jon Cryer, Rachel Maddow, Roy Haynes

S18E85 - Neil Patrick Harris, Mike Birbiglia, Neil Peart

S18E86 - Adm. Michael Mullen, Top Ten by Betty White, Black Joe Lewis & the Honeybears

S18E87 - Ryan Reynolds, chef Eric Ripert and the cast of the Broadway musical Anything Goes

S18E88 - Jim Carrey, Rosie Huntington-Whiteley, Todd Rundgren

S18E89 - Samuel L. Jackson, Texas Ranger Josh Hamilton, Jennifer Hudson

S18E90 - Cameron Diaz, Eddie Vedder

S18E91 - Jason Bateman, Amy Sedaris, Top Ten by Keith Olbermann, Drive-By Truckers

S18E92 - Kevin James, pet fashion designer Ada Nieves, Beady Eye

S18E93 - Jason Segel, horse whisperer Buck Brannaman, Noah and the Whale

S18E94 - Shia LaBeouf, Bert Kreischer, Dawes

S18E95 - Tom Hanks, Sleepy Man Banjo Boys

S18E96 - Patrick Dempsey, Erica Hill, Marty Stuart

S18E97 - Julia Roberts, Cake

S18E98 - Emma Watson, George Lopez, Incubus

S18E99 - Roseanne Barr, Tom Felton, Blake Shelton

S18E100 - Ryan Gosling, Gomez

S18E101 - Kyra Sedgwick, Tim Harmston, Nikki Jean

S18E102 - Bono & the Edge, a performance from Spider-Man: Turn Off the Dark

S18E103 - Steve Carell, Hope Solo and Abby Wambach, The Del McCoury Band and the Preservation Hall Band

S18E104 - Jeremy Piven, Captain Luis Montalvan, Cee-Lo Green

S18E105 - Harrison Ford, Porcelain Black

S18E106 - Brian Williams, Tim Robbins & the Rogues Gallery Band

S18E107 - Julianne Moore, Johnny Galecki, Tanner Foust, Eels

S18E108 - Craig Ferguson, Connie Britton, Anna Calvi

S18E109 - Kirstie Alley, Louis C.K., Fountains of Wayne

S18E110 - James Franco, Dianna Agron, Christina Perri

S18E111 - Ricky Gervais, Cat Deeley, Explosions in the Sky

S18E112 - Emma Stone, Alan Mulally, Sallie Ford

S18E113 - Colin Farrell, Christopher Ferguson, Typhoon

S18E114 - Denis Leary, Elizabeth Cook, Drum Solo Week II kicks off with Tony Royster Jr.

S18E115 - Rachel Maddow, Rose Byrne, Gavin Harrison

S18E116 - Ashton Kutcher, Rafael Nadal, Stewart Copeland

S18E117 - Paul Rudd, Bill Burr, Dennis Chambers

S18E118 - Jason Sudeikis, Bettina Luescher, St. Vincent

S18E119 - Alec Baldwin, Joe Namath, Lenny Kravitz

S18E120 - David Arquette, Aubrey Plaza, Thurston Moore

S18E121 - Julianna Margulies, Joe Wong, Lady Antebellum

S18E122 - Kim, Kourtney & Khloe Kardashian, Michael Emerson, The Jim Jones Revue

S18E123 - Sgt. 1st Class Leroy Petry, Sarah Jessica Parker

S18E124 - Michael J. Fox, Top Ten by the cast of Two and a Half Men, Jim McDonald, John Doe

S18E125 - Dr. Jill Biden, Ted Danson

S18E126 - Jonah Hill, Paula Abdul, Coldplay

S18E127 - Taylor Lautner, Minka Kelly, Wilco

S18E128 - Sergeant Dakota Meyer, Sofia Vergara, Chris Cornell

S18E129 - Nathan Fillion, Larry Miller, The Jayhawks

S18E130 - Seth Rogen, Poppy Montgomery, Fleet Foxes

S18E131 - Jack Hanna, Anna Faris

S18E132 - Anderson Cooper, Nick Offerman, The Knux

S18E133 - Kaley Cuoco, Skipper Bivins & Trent Jackson, Death Cab for Cutie

S18E134 - Samuel L. Jackson, Karen Rontowski, Anne-Sophie Mutter

S18E135 - Brian Williams, Sting

S18E136 - Hugh Jackman, Sean Young, Feist

S18E137 - George Clooney, Mastodon

S18E138 - Caroline Kennedy, dock diving dogs, The Joy Formidable

S18E139 - Bryan Cranston, Jeff Altman, Garland Jeffreys

S18E140 - Tracy Morgan, Mike Golic & Mike Greenburg, Mates of State

S18E141 - Matthew Broderick, horse wrangler Erin Bolster and her horse Tonk, Hunter Hayes

S18E142 - Bill Clinton, Deer Tick

S18E143 - Bill O'Reilly, Martina McBride

S18E144 - Artie Lange, Eddie Brill, Beirut

S18E145 - Salma Hayek, Keith Olbermann, Jane's Addiction

S18E146 - Eddie Murphy, Jane Levy, Mayer Hawthorne

S18E147 - Justin Timberlake, Jennifer Esposito, The Civil Wars

S18E148 - Johnny Depp, Foster the People

S18E149 - Tom Brokaw, Myq Kaplan, The Head & The Heart

S18E150 - Tony La Russa, Jesse Eisenberg, Puscifer

S18E151 - Ben Stiller, Whitney Cummings

S18E152 - Condoleezza Rice

S18E153 - Mark Harmon, Mike Judge, Top Ten by Matt Lauer, Eli Young Band

S18E154 - Bill Cosby, Jason Isbell and The 400 Unit

S18E155 - Melissa McCarthy, Anthony Bourdain, Joan Baez & Kris Kristofferson

S18E156 - Robert Pattinson, Annie Leibovitz, David Crosby and Graham Nash

S18E157 - Adam Sandler, Peter Gabriel

S18E158 - Stupid Humans Tricks, Katie Holmes, Noel Gallagher's High Flying Birds

S18E159 - Steve Martin, Felicity Jones, Lonesome River Band feat. Steve Martin

S18E160 - Jason Segel, Jamie Oliver, The Kooks

S18E161 - Bill Maher, Nikki Reed, Foo Fighters feat. Joan Jet

S18E162 - Jerry Seinfeld, Lykke Li

S18E163 - Regis Philbin, John Fogerty

S18E164 - Herman Cain, Grouplove

S18E165 - Andy Kindler, Ty Burrell, Gayle King, Needtobreathe

S18E166 - Amy Sedaris, Christopher "Mad Dog" Russo, Sondre Lerche

S18E167 - Justin Bieber, Brian Regan, FreeSol

S18E168 - Jonah Hill, Kristen Johnston, Ryan Adams

S18E169 - Matt Damon, Shelby Lynne

S18E170 - Jessica Biel, Tom Dreesen, The Black Keys

S18E171 - Charlize Theron, Kevin Nealon, Blitzen Trapper

S18E172 - David Duchovny, Comedian Hugh Fink, Young Jeezy

S18E173 - Scarlett Johansson, Julie Chen, Top Ten by the 2011 Heisman Trophy winner Robert Griffin III

S18E174 - Barbara Walters, Bill Hader, Wild Flag

S18E175 - Robert Downey Jr., Rooney Mara

S18E176 - Tom Hanks, My Morning Jacket

S18E177 - Jude Law, Bob Sarlatte, Gary Clark Jr.

S18E178 - Tom Cruise, Anthony Hamilton, Top Ten by Mitt Romney

S18E179 - Harry Connick Jr., Scott Van Pelt, Mariachi El Bronx

S18E180 - Jon Huntsman, J. Cole

S18E181 - Anderson Cooper, Lindsey Vonn, Childish Gambino

S18E182 - Jay Thomas, David Hyde Pierce, Darlene Love