The Joker's original appearance didn't have any acid flowers or gags. He only had guns and knives, and the Joker venom. The venom was the closest thing to a gimmick he had. And the only time he laughed was when he thought he was dying. Heath's Joker is nowhere near that serious. He laughs when he's driving his slaughter truck and throwing Rachel out the window, he goofs off at the party, and he goes to the hospital dressed in a tacky nurse's outfit. And then there's the whole pencil trick thing, which is pretty funny in a very twisted way.
Considering where you're making this post, nice trolling.
Batman Begins was never meant to be realistic.

Nor was TDK, really. They are meant to have a more
realistic tone, and that's all. Think Blade Runner. Realistic tone, but still very much a fictional world. That's what Nolan was going for all along, which is why he had the crew of the movie watch Blade Runner before they began working on the film. Really, if Nolan thinks Batman and his vehicles could do all the things that they do in these movies, he's an idiot. But he obviously knows better than that, and I do wish people would stop exaggerating on the whole realism issue.