This entire showdown with the Gotham PD under Brendon and Loeb's ill-conceived direction, ending with Batman kicking all of their collective asses, is among the highlights of the story. It is the moment that Batman changes in the public's eye from a crazy vigilante to the Dark Knight that no evildoer is a match for.
It also boasts the first (and so far, limited) appearance of Batman's sonic wave emitter summoning a swarm of bats. You know this is awesome when Batman Begins pitched it as one of its key scenes.
Batman's first salvo against the mob's upper echelons also qualifies. They're sitting down to dinner, talking about how Batman isn't a threat. So far, all he's done is take down low level mooks, not something that concerns them, and that since it makes the people feel safe, they think that he might be a good thing to have around, and how the real problems are Harvey Dent and Jim Gordon. Batman proceeds to cut the lights, blow up the outer wall and give this badass speech to the now terrified gangsters and corrupt officials:
Batman: Ladies. Gentlemen. You have eaten well. You have eaten Gotham's wealth. Its spirit. Your feast is nearly over. From this moment on, none of you are safe.
Gordon gets the crap beaten out of him by a group of dirty cops. He returns the favor with his bare hands.
Throughout the early acts of the book, Gordon has done a grand job of telling us that his crooked partner, Detective Flass, is a Green Beret, and that fighting him would probably be a dumb choice. So when Gordon looks for payback, he tosses Flass a baseball bat, and destroys him.
Before doing so, he explains that it's been a long time since he's had to take down a Green Beret. So he's not concerned that he has to fight someone with such training, only that he might be a little rusty since the last time he had to whip one.
A small one, but an awesome point has to be given to the young DA, Harvey something or other, for refusing to cave to pressure from the corrupt Gotham PD… and making himself a clandestine ally of the Batman as well.