The Hulk needs to sneak into an Army base. His solution: Grab a truck, smash it down over himself like Solid Snake in his cardboard box, and walk into the base pretending to be the car. It works.
Savage Banner. Imagine all of the Hulk's strength, but put in Bruce Banner's tiny body, and then imagine it wreaking havoc. Actually doing it is better than imagining it.
Joe Fixit. Basically the Hulk dressed up like a spiffy gangster, he's usually spending his time spitting out one-liners while happily wreaking havoc upon the city. There's just something really hilarious, and satisfying, about smashing up the city while saying lines like:
Joe Fixit: Does this bug you? Does this bug you? Does this bug you?
Joe Fixit: Face it. I'm funny, and you're not.
Joe Fixit: Love me, love my fists!
When you first attract the attention of the police near the beginning of the game, you hear police dispatch: "Suspect is Bruce Banner. About twelve feet, green skin." What makes it is the completely deadpan tone like this was nothing unusual.