8. Dwayne "The Rock" Johnson
Everything the Rock touches tends to turn to gold these days, so it's quite surprising that he hasn't already made his Simpsons bow. That said, he'd make a great character on the show so it really should happen! Who wouldn't want to see an animated People's Eyebrow? Wouldn't Homer receiving a Rock Bottom be great television? What isn't to like about an on-screen rivalry between Rainier Wolfcastle and the Rock for the title of "best action star"? Essentially, a Dwayne Johnson appearance on The Simpsons would be epic - especially if he brought with him his classic World Wrestling Entertainment catchphrases and persona. And, I don't really know why, but I also imagine that an encounter between the Rock and Krusty the Klown would be hilarious.