At first, celebrities didn’t seem to want to appear on “The Simpsons.” In fact, a couple of the first celebrities to lend their voices, Dustin Hoffman and Michael Jackson, used pseudonyms for their roles. Then, of course, the show became a huge success, and suddenly stars were jonesing to get on the show. Some of them play characters, but others make appearances as themselves. With that in mind, here are our favorite celebrity cameos on “The Simpsons,” but only where the celebrities were on the show as themselves. There will be some pileup in terms of episodes, because usually if one appears, a few more are on there as well.