Its hard to draw the line between possible/impossible aspies ; NTs can be shy, eccentric and have deep passions too. But out of those Snoopy mentionned and I could somehow agree they might be aspies :
Jimi Hendrix : He sure was aspie-like in many ways. He was obsessive about playing guitar (once played 36 hours straight), he had facial mimics when playing, he was perfectionnist and was prone to criticism (could constently ask his friends if his hat, jacket or pants were ok). Bob Dylan was also is idol, and in a documentary Ive seen, one of his ex-girlfirend reported he could talk about him for hours without her showing any interest.
Marylin Manson : Althought I profoundly dislike the guy, I know he was a shy nerdy kid who played dungeons and dragons and was frequently in his fantasies.
Courtney Love : Not so sure as I dont know much about her, but Ive yet to find something that could disqualify her being an aspie.
Keanu Reeves : Doesnt he have an official diagnosis? Its not the first time I hear he is asperger.
Neil Young : Im a big fan of Neil Young and also thought he might possibly be. I dont know much about his personality, but he sure has the look.
Others I have heard are/were most certainly aspies, and even evaluated by professionals : Albert Einstein, Isaac Newton, Beethoven, Mozart (he was bipolar, aspie Im not sure), Andy Warhol, Sid Barrett (Pink Floyd), Immanuel Kant, Emily Dickinson, the singer from The Vines, Dan Akroyd, Bill Gates... and other I cant remember.
One guy few might know but I believe to be an aspie is Greg Graffin, singer of Bad Religion. He's been one of my idols for quite a few time as I can relate to him in so many ways. Whenever he speaks he tries to be "intellectually correct" more than showing off or try to be kind. He also has an extended vocabulary and a great interest in scientific matters (he owns a PhD in biology). When he's singing on stage, he can look quite gooffy and makes crazy signs with his hands, which almost look like stims. Check him out and tell me what you think (he's the guy singing, of course):
http://www.youtube.com/watch?v=S_Ft7LVCmDI