4. Whose Line is it Anyway ? Originally beginning as a radio show and later making the jump to TV in 1988, Whose Line is it Anyway was an improvisational panel show which gave its contestants the freedom to create spontaneous scenarios out of random topics. The show became a launching pad for many up and coming comedians, such as Paul Merton and Josie Lawrence, but it also frequently included appearances from veteran comics like Peter Cook and Stephen Fry. Perhaps more than anything else, Whose Line is it Anyway became well known for its regular turns from improv masters Colin Mochrie and Ryan Stiles. With falling viewing figures, the show was cancelled in 1998, but it soon found a second life when the concept was picked up by US Network ABC the same year. UK host Clive Anderson was replaced by Drew Carey, but the overall format remained largely unchanged - complete with returning regulars Mochrie and Stiles. Much like the UK version, the hit show managed to attract notable guest stars like Robin Williams and David Hasslehoff, appearing in memorable episodes which continue to be repeated regularly. Whose Line US was cancelled in 2007, but it remains a fine example of how a UK show can travel across the Atlantic without any major changes.