Has to be Gotham City mayhem, where he confronts Penguin and Catwoman for the first time. That exchange between Batman and Penguin is classic:
Batman: "Admiring your handy work?"
Penguin: "Touring the riot scene. Gravely assessing the devastation. Upstanding Mayor stuff"
Batman: "You're not the Mayor"
Penguin: "Things change"
Batman: "What do you want?"
Penguin: "Ah, the direct approach. I admire that in a man with a mask. You don't really think you'll win, do you?"
Batman: "Things change"
The rooftop battle with Catwoman is also awesome.