I don't think anybody has brought this up for like two years now, and I'm sure there's been plenty of discussion about it already. But I want to talk about Bruce Banner's hulking-out in The Avengers. Specifically, I want to respond to a criticism I heard of the movie a few times shortly after it came out: that it was a cop-out, that it didn't make sense that, on the helicarrier, he would hulk out accidentally and be unable to control his violence, but in New York, he can do it on purpose and is in total control.
First of all: I don't even understand the "he shouldn't be able to just hulk out at the end" argument. Like, being sometimes unable to stop yourself doing a thing and being able to do that thing when you want to are obviously compatible. Insofar as the Hulk is a metaphor for anger management problems, (which, like, obviously?) it wouldn't make sense for that not to be the way it works.
Secondly: On the helicarrier, he was violent towards people who were antagonistic towards him. I'm not saying the Hulk's responses are justified, but it makes sense that it would be infuriating when the person who manipulated you onto the ship tries to manipulate you into calming down out of obvious self-interest. Bruce was already in that headspace: it was bullshit for Natasha to try and get him not to respond in a totally predictable way to a situation he wanted to avoid, but that she did her very best to put him in.
As for Thor, he hit him with a hammer then told him to "Try to think." He wasn't exactly tactful. (Again, not ethically justified, but makes narrative sense.)
And the planes? They were shooting him.
In New York, on the other hand, there was a clear and easy target for his violence: the invading army. Being consistently provided with targets to funnel his anger into, the Hulk was totally capable of choosing to damage the people he was particularly pissed at in that moment, and not the people who were also attacking his chosen targets.
I've seen a lot of quotes floating around Tumblr of the book "Why does he do that?" by Lundy Bancroft. In it/in them, (because I haven't read the book itself I can only speak to the content of the quotes) he points out that violent and abusive men are generally entirely aware of and in control of what specific harm they're doing. They act the way they do because, deep down, they think it's rational and okay.
The Hulk isn't incapable of thinking. He isn't incapable of directing his violence. He's a fully conscious agent who thinks that extreme violence is acceptable in any scenario where he feels it could possibly help him.