6. Sacha Baron Cohen
Sacha Boran Cohen has actually already contributed to The Simpsons when he voiced the tour guide Jakob in the episode "The Greatest Story Ever D'ohed". However, he is yet to appear as himself. Boran Cohen is huge in the States and his star has never shone brighter than it is currently, following on from his latest public shenanigans at the BAFTA Britannia Awards in Hollywood recently, where he apparently shoved an elderly actress off the stage during an acceptance speech (it was all a joke, obviously). It would be great if he appeared as himself, but arguably even better if he was to appear as one of his own characters, such as Bruno, Ali G, Admiral General Aladeen or Borat (especially Borat). Having Borat staying with the Simpsons, for example, and adapting to their ways would be absolutely hilarious. But there are, of course, many other ways that Baron Cohen could be utilised aside from playing an original character like he has done before.