Everything in "Urinetown" is hilarious, but I think this is my personal favorite:
Little Sally: "What kind of musical IS this?! The good guys finally take over and then everything starts falling apart??"
Officer Lockstock: Like I said, Little Sally, this isn't a happy musical.
Little Sally: But the music's so happy!
Officer Lockstock: Yes, Little Sally. Yes it is.
I also like this one from "The Producers":
"I want you to know, my dear, that even though we're sitting down, we're giving you a standing ovation."
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