Ralph: I bent my wookie
The episode where Bart is accused of stealing from the collection plate at church and he is hiding out in the treehouse. He makes a statement that everyone is out to get him or something like that and just then an old guy pokes his head up in the window and says "Thief" Cracks me up all the time.
Halloween episode with "The Shinnin. Don't you mean the shining? No, wee'll git a sooot."
so many more, i'll post some more later :)