In this day and age, the level of an individual's celebrity can often be measured by whether or not they have appeared in The Simpsons. A guest voice on the show (playing a new character) is one thing, but appearing on the show as themselves is another level entirely. Paul and Linda McCartney, Cypress Hill, the Smashing Pumpkins, Leonard Nimoy, Kim Basinger, Jerry Springer, Mark Hamill, Cyndi Lauper, Ron Howard, Dolly Parton, Elton John, Stephen Hawking, Lucy Lawless, Mel Gibson, Kid Rock, Willie Nelson, Stephen King, Andre Agassi, Pete Sampras, Venus and Serena Williams, Paul Newman, Richard Gere, Wolfgang Puck, Stan Lee and Carmen Electra (I could go on and on and on...) amongst many others have appeared as themselves on the ever-popular animated series, with varying levels of prominence and success, but we still love a fresh celebrity appearance despite the fact that many have already been there before. With that in mind, let's take a look at ten celebrities who it would be great to see appearing as themselves on The Simpsons...
10. Trey Parker & Matt Stone
Trey Parker and Matt Stone are, of course, the creators of South Park, so it would simply be a cool proposition to have them appear in a long-standing friendly rival of their own show. Simpsons creator Matt Groening and Parker and Stone have a mutual respect for each other and it would be a nice touch to see them contributing to each other's work with a respectful appearance in each other's work. I'm sure they could work a neat little in-joke in to their scene, but even just a small cameo with the duo in a shop, a restaurant or even just walking down the street having a discussion would be a very welcome inclusion in the show. Such an appearance from the pair on Family Guy seems very unlikely to happen - given that they have openly criticised the show - but an appearance on The Simpsons is well within the realms of possibility.