Most recurring Simpsons characters got at least one moment to shine in the movie — from Krusty the Clown, to Hans Moleman ... enemy Dr. Demento Sideshow Bob. Bob Terwilliger is obviously ...

Read more: The Simpsons Showrunner Admits ... Kelsey Grammer did when he first played Sideshow Bob — former right-hand man to Krusty the Clown and Bart's ultimate arch-enemy.

with some of Hollywood's biggest names stepping into the booth for one-off Simpsons appearances. But none of them have ever made an impact quite like Kelsey Grammer did when he first played Sideshow ...