9. Sideshow Bob - Les Miserables 24601
This one is a reoccurring Easter egg in the show which crops up in many Sideshow Bob related episodes. Sideshow Bob is one of the best loved supporting characters in The Simpsons, his constant foiled attempts at murdering Bart and his various encounters with rakes have made him a constant source of laughs and drama. Its no secret that Sideshow Bob has quite the taste for musicals so it is a fitting reference that his prison identification number is 24601, a reference to the jail number (and song) of Jean Valjean from Victor Hugos iconic Les Miserables. Keep an eye out for this next time you see Bob in a jail cell.