MOST FAMOUS: Reality show moments

Celebrity: A 21st Century Story (9pm, BBC2) charts the explosion of reality TV and here, we pick our best moments from the shows that shaped our obsession with keeping it ‘real’…

Big Brother (2000-18) This game-changing show featured a house full of unknowns, who were filmed 24 hours a day. Over its initial tenyear run on Ch4, it was the making of reality stars including Alison Hammond and tragic Jade Goody. It also spawned a celebrity spin-off, which gave us fake celebrity Chantelle Houghton – and George Galloway MP pretending to be a cat.

The Osbournes (2002-05) The chaotic domestic adventures of Ozzy, Sharon and two of their children, Kelly and Jack, this paved the way for The Only Way Is Essex, Keeping Up With The Kardashians and others.

Ozzy’s family became infinitely more famous after baring all on the show. Sharon even went on to be a judge on The X Factor…

The X Factor (2004-present) Currently on hiatus, this was the dream ticket for many contestants, including Rylan Clark, One Direction and Leona Lewis. However, a 2010 audition ended in a fistfight – between former friends Abbey and Lisa, aka Ablisa.

Britain’s Got Talent (2006-present) Along with The X Factor, this show gave ordinary people a shot at stardom. Audiences got used to laughing at embarrassing auditions, but in 2009, they had to change their tune when Susan Boyle (centre) belted out her unforgettable I Dreamed A Dream.