I have to say that one of my all-time favorite episodes is the one where Side-Show Bob is on parole, and he is after Bart.
Soooo many quotes in that one, for example:
(When Sideshow was sending the death threats)
Homer: "Ahhhhhhhh, someone wants to kill me....oh wait its for Bart"
FBI Agent: "Ok, when I say hello Mr. Thompson, and stomp on your foot, you smile and nod"
Homer: "Gotcha"
FBI Agent: "Hello Mr. Thompson"
Homer: (turns to the other agent) "I think he's talking to you."
Parole Board: "What about that tatoo on your chest that says Die Bart Die?"
Sideshow Bob: "No, that's German for 'Di Bart Di'"...
Parole Board: "Well, no one that speaks German can be an evil man....Parole Granted"....
There is sooooo many more from that episode, hehehehe