The Original Episode of 8 Out of 10 Cats Does Countdown which was aired during Channel 4's Mash-Up Week

Jimmy Carr, Sean Lock and Jon Richardson take on the famous words and numbers quiz. Jimmy Carr hosts proceedings, and Sean Lock faces Jon Richardson in a rematch of the original encounter. David O'Doherty is in Dictionary Corner along with Countdown regular Susie Dent. Meanwhile the country's favourite boffin Rachel Riley provides the letters and numbers with a little help from comedian Joe Wilkinson.

Jon Richardson and special guest captain Lee Mack are joined by celebrity guests Henning Wehn and David O'Doherty. Countdown regular Susie Dent is joined by Vic Reeves in Dictionary Corner, while Rachel Riley provides the letters and numbers with a little 'help' from comedian Joe Wilkinson.

Jimmy Carr hosts this festive edition as Sean Lock and Kathy Burke take on Jon Richardson and David Baddiel. Alex Horne and The Horne Section joins Susie Dent and Rachel Riley.

Jimmy Carr hosts this festive edition as Sean Lock and Johnny Vegas take on Jon Richardson and Katherine Ryan. David O'Doherty joins Susie Dent and Rachel Riley.

Jimmy Carr hosts this festive edition as Sean Lock and Kathy Burke take on Jon Richardson and Russell Howard. Joe Lycett joins Susie Dent and Rachel Riley.

Jimmy Car hosts while Johnny Vegas and Sara Pascoe take on Jon Richardson and Richard Osman . Susie Dent is joined by David O'Doherty in Dictionary Corner, with Rachel Riley and Joe Wilkinson.

Jimmy Carr hosts a special version of the game show to tie in with the General Election. Team captains Jon Richardson and Alan Carr are joined by guests Romesh Ranganathan, Sarah Millican and John Kearns.

Jimmy Carr hosts as Jon Richardson and Catherine Tate take on Sean Lock and Joe Wilkinson. Joe Lycett joins Dictionary Corner, with Susie Dent and Rachel Riley.

Jimmy Carr hosts as Sean Lock and Kathy Burke take on Jon Richardson and David Mitchell. Plus James Acaster and Joe Wilkinson join Susie Dent and Rachel Riley.

Jimmy Carr hosts the special Christmas edition, while Sean Lock and Bob Mortimer take on Jon Richardson and Lucy Beaumont. They are joined by guests Adam Buxton, Joe Wilkinson, Susie Dent and Rachel Riley.

A chance to watch top moments from the comedy game-show mash-up, with guests including Richard Ayoade, Aisling Bea, Alan Carr, David Mitchell, Katherine Ryan and Johnny Vegas.

A chance to watch top moments, as comedians including Kevin Bridges, Roisin Conaty, Joe Lycett and Joe Wilkinson join Jimmy Carr, Susie Dent and Rachel Riley.

Jimmy Carr, Susie Dent and Rachel Riley host a festive edition. Jon Richardson and Sarah Millican take on Sean Lock and David Mitchell. With guest David O'Doherty.

A classic episode of '8 Out of 10 Cats Does Countdown' featuring the best of Sean Lock

Jimmy Carr hosts a festive edition, as Jon Richardson and Sarah Millican take on Lee Mack and Jason Manford. With Nick Mohammed, Joe Wilkinson and Countdown regulars Susie Dent and Rachel Riley.

Jimmy Carr hosts a combination of the comedy panel show and the long-running words and numbers quiz, inviting Jon Richardson and Jack Dee to take on Lee Mack and Rose Matafeo in a festive-themed edition. They're joined by guests Stevie Martin and Joe Wilkinson, and Countdown regulars Susie Dent and Rachel Riley.

Sean Lock, Bob Mortimer, Harry Hill, Joe Lycett, Jon Richardson, Lucy Beaumont, Katherine Ryan and more take on the words and numbers in this best-bits compilation episode.

Sean Lock, Bob Mortimer, Jon Richardson, Lucy Beaumont, Rosie Jones, Victoria Coren-Mitchell and more take on the words and numbers in this best-bits compilation episode.

Jimmy Carr hosts as Cats Does Countdown does Christmas. Joe Lycett and Danny Dyer play Jon Richardson and Roisin Conaty. With Mr Swallow and Joe Wilkinson.

Jimmy Carr and Jon Richardson are joined by a host of top comedians for a compilation of best bits from Cats Does Countdown, including Lee Mack, Sarah Millican, Alan Carr, Richard Ayoade, Katherine Ryan, Tom Allen, Judi Love, Nick Mohammed, Jonathan Ross, Rose Matafeo and Sam Campbell, along with regulars Joe Wilkinson, Susie Dent and Rachel Riley.

Some best bits featuring Richard Ayoade, Judi Love, Lee Mack, Jon Richardson, and more.

Some best bits, from Danny Dyer, Joe Lycett, Judi Love, Rhod Gilbert, and many more.

Some best bits featuring Alan Carr, Maisie Adam, Joe Wilkinson, Katherine Ryan and more.

Jimmy Carr hosts a special Christmas edition of 8 Out Of 10 Cats Does Countdown, packed with festive surprises. Jon Richardson and Daisy May Cooper take on Rob Beckett and Judi Love. Katie Norris joins Susie Dent in Dictionary Corner. And as festive tradition dictates, Joe Wilkinson hinders Rachel Riley with the letters and numbers.