5. Karl Pilkington
Like Boris Johnson, Karl Pilkington isn't known in America, but I can't help but think that it would be a brilliant idea to have him appear in The Simpsons. Ricky Gervais is huge in the States and, as Gervais' little pet project, it really wouldn't be that difficult to make people aware of who Pilkington was and what he was about. I feel as if Gervais should push to have Pilkington imposed on American audiences, so maybe he could use his connections to the show (he wrote and guest starred in the episode "Homer Simpson, This Is Your Wife", voicing the character Charles Heathbar, and also guest starred as himself in the Season 22 episode "Angry Dad: The Movie") to make a Pilkington appearance possible. It could even be presented as an episode of An Idiot Abroad, with Pilkington taking in the culture of a typical, small American town. I'm undecided on how I think it would go down with American audiences, but it would definitely pull in the Brits and if Pilkington could be presented to American audiences by Gervais prior to his potential appearance on The Simpsons, I'm sure his clueless exploits would come across as funny (and his little perfectly-round head would look hilarious as a Simpsons-style drawing).