Career: Carr began performing on the stand-up circuit, doing up to 300 shows a year for three years, before taking his act to the Edinburgh festival in 2002. This brought him to the attention of TV bosses, and before long he was presenting series such as Your Face or Mine and Distraction. Since then, he's rarely been off TVscreens, hosting the first run of the Friday Night Project, 8 Out of 10 Cats and numerous Channel 4 list shows. He's also made a move into acting, appearing in Alien Autopsy, Confetti, Stormbreaker and Telstar. He is one of Britain's busiest comics and his DVDs are big sellers.

Career: Riley's big break came in 2008 when she was chosen from more than 1,000 applicants to replace Carol Vorderman on Countdown. She presented her first show alongside Jeff Stelling in January 2009, and reached her 1,000th episode in June 2013. Away from the numbers and letters on Countdown, she began co-hosting The Gadget Show alongside Jason Bradbury in June 2013. She was a contestant on Strictly Come Dancing in 2013 and was the fifth celebrity to be eliminated.

Career: Lock's first professional TV appearance was in 1993, when he appeared in a supporting role alongside Rob Newman and David Baddiel on their signature TV show Newman and Baddiel in Pieces. He toured with the duo as their support act and, as a result, became the first comedian to perform at Wembley Arena. He script-edited the 1998 BBC Two series Is It Bill Bailey? and had his own show on BBC radio, 15 Minutes of Misery. It was later expanded into the half-hour series, 15 Storeys High. He's now a team captain on the panel game 8 Out of 10 Cats. Other game show appearances have come in the likes of The Big Fat Quiz of the Year, Have I Got News for You, QI, and They Think It's All Over. He also hosted his own entertainment show on Channel 4 called TV Heaven, Telly Hell.

Career: Carr made his TV debut as a guest on the ITV lunchtime show Today with Des and Mel. He came to true prominence on Channel 4's The Sunday Night Project with Justin Lee Collins. He makes regular guest appearances on panel shows such as 8 Out of 10 Cats and Never Mind The Buzzcocks and has featured as a panellist on Channel 4's annual Big Fat Quiz of the Year, a staple of the Christmas TV schedules. He has also fronted his own game show, Alan Carr's Celebrity Ding Dong, written his autobiography, and continues to perform stand-up. His Channel 4 show Chatty Man attracts some of the biggest names in showbiz and has been a staple of the Channel 4 schedule since 2009. He also presented a weekly programme on Radio 2 for three years, and fronted game show The Singer Takes It All. In 2016, he hosted Alan Carr's Happy Hour, which was a spin off of Chatty Man.

Career: Her debut Edinburgh Festival Fringe show, Sarah Millican's Not Nice, won the if.comedy award for Best Newcomer in 2008; she hasn't looked back since. She has appeared as a panellist on 8 Out of 10 Cats, Have I Got News for You, You Have Been Watching and as a performer at The Secret Policeman's Ball 2008 and 4 Stands Up. She was featured in the Manchester edition of Michael McIntyre's Comedy Roadshow, broadcast in June 2009, and provided vocal work to the BBC's natural history footage for Walk on the Wild Side. She briefly joined the Loose Women panel in January 2011 and launched her own show, The Sarah Millican Television Programme, in 2012.

Career: Osman has worked behind the scenes as an executive producer on a number of TV programmes, including Deal or No Deal, 8 Out of 10 Cats, and 10 O'Clock Live. As the UK creative director of TV production company Endemol, he pitched the quiz Pointless to the BBC. As a way of explaining the rules, he played the co-host during a run-through. He was asked to do the role for real when the show was commissioned. Pointless started on BBC Two in 2009 and was an immediate hit. It quickly made the switch to BBC One. Since being in the spotlight on Pointless, he has made guest appearances on QI, Have I Got News for You and Would I Lie to You? He also guest presented an episode of The One Show alongside Alex Jones.