What, no Sideshow Bob quotes yet? He's one of my favorites!
Parole Board lady: "What about that tatoo on your chest, doesn't it say 'Die Bart, die'?"
Bob: "No, that's German for, 'The Bart, the.'"
Parole Board lady: "Oh! No one who speaks German could be an evil man!"
Bart: "You have such a beautiful voice. Would you sing the entire score to the HMS Pinafore?"
Bob: 'Very well Bart. I shall send you to Heaven before I send you to Hell!"
Bob: "Darn it Bob, there were plenty of brand-new bombs, but no, you had to go for that retro 50's charm."
Bob: "Rakes. My old archnemisis."
Bart: "I thought I was your archnemisis."
Bob: "I have a life outside of you, Bart."
Bob: "You do know I used to have a…problem with…trying to kill people."
Cecil: "Goodness, I had no idea! For you see, I have been on Mars for the last decade, in a cave, with my eyes shut and my fingers in my ears."
Bob: "Touché, Cecil."
Bob "The truth? You can't handle the truth. No truth-handler, you! Bah! I deride your truth-handling abilities!"