Character Analysis
We're just going to say it: scruffy Mark Ruffalo (Mark Scruffalo?) makes the best Hulk. Sure, Edward "Tyler Dirden" Norton was good. And Eric Bana was a-okay. But Mark Ruffalo—a dude who exudes a kind of everyman good hearted-yet-nervous energy—is awesome.
Probably because Bruce Banner is a dude who also exudes an everyman good-hearted-yet-nervous energy.
Thor and Tony Stark want to be masters of the universe. Captain America wants to be Super Good. Black Widow wants to kick butts and take names. Hawkeye wants to…um…shoot arrows?
Dr. Banner, on the other hand, wants to find a nice, cozy rock to go live under.
He probably carries more raw power than all of the other Avengers put together—some accounts hold that the Incredible Hulk is one of the most powerful beings in the Marvel Universe—but he can't control it. So he's doing his best just to not get noticed, hoping that "the other guy," as he calls the Hulk, won't come thundering out to play.
The interesting thing is, SHIELD doesn't want the Hulk. They want Dr. Banner, who's the only guy in the world who can help them track the Tesseract. Sadly, it's a package deal…and so they take steps to contain the Hulk if they need to. Just in case.
That puts the Hulk is an odd position: potentially more destructive than any villain, but able to do wonders when pointed in the right direction. That's the trick Bruce Banner needs to figure out.
In the meantime, he's Marvel's equivalent of Dr. Jekyll and Mr. Hyde: the mild-mannered scientists hiding a monster inside. But despite that fact that the Big Green Rage Machine has to compete with a lot of other characters for our attention, he's the guy who probably goes through the most growth and development.
Banner ultimately accepts the Hulk, acknowledges that it's a part of him, and in so doing, gains the ability to control the change when he needs to…most impressively, during the big finale.
CAPTAIN AMERICA: Dr. Banner…now might be a really good time for you to get angry.
BRUCE BANNER: That's my secret Captain: I'm always angry.
It's a great moment, and it shows what Dr. Banner has learned about himself in the time since The Incredible Hulk (and the time he went from being Edward Norton to Mark Ruffalo). That's one of the reasons Marvel films are so good: they always find ways to make a one-note rage machine into a much, much more interesting character.