10: Tara Palmer-Tomkinson

Even Frank Skinner was appalled by the writhing, gurning Tara Palmer-Tomkinson who turned up on his show in 1999. Claiming to be stoned, she started yelling uncontrollably before saying: "My brain cell has packed up again." To which Skinner replied: "I know."

9: Robert Downey Jr

That nice Lorraine Kelly was gobsmacked in 2005 when Robert Downey Jr began his This Morning interview by saying "your tits look great". As the nation’s mouths hung open, Lorraine made matters worse by blurting: "I didn’t realise they were so out." Moving swiftly on...

8: David Icke

A battle of wills unfolded when David Icke turned up on Wogan in 1991. Comparing himself to Jesus, the former sportscaster told Wogan that the Apocalypse would kill millions by the end of the year. He then congratulated the audience on being able to laugh despite the news, at which point Terry observed: "They’re laughing at you David, not with you." Which was a very fair point.