10 Best Ever Guest Stars In The Simpsons

1. Kelsey Grammer As Sideshow Bob

Sure, at this point, Kelsey Grammer's "Sideshow" Bob Terwilliger is practically a regular in his own right, but could there be any other choice? Though he appeared briefly (and silently) as Krusty's loyal sidekick in the earliest episodes of the show, season one's "Krusty Gets Busted" gave Springfield's favorite felon (sorry, Snake) his own voice -- and it was a beautiful one. Attempting to frame Krusty was only the beginning -- in subsequent episodes, Bob would try to kill Aunt Selma, fix the Springfield mayoral election, blow up television in the town, kill Krusty, switch faces with a cellmate, go straight, and of course, kill Bart. Time and time again, though, Bob's antics are foiled by a hyperactive, underachieving ten-year-old boy, and it just makes him angrier and angrier. The character would never have worked so well without Grammer's booming voice and perfect diction. Bob's cultured background, Harvard education, and conservative air all come through in his voice, as does his cartoonish villainy -- after all, we first learn Bob is evil in "Krusty Gets Busted" when his fake tears turn into an unsettling cackle. Grammer, too, has won an Emmy for his work on The Simpsons -- and it's possible more are on the way. Best line: Too many to choose, but for pure pleasure, I'm going with the excerpts from H.M.S. Pinafore