I understand you question.

I do not know. But here's the thing; at least MOS made an impression on you, for good or bad. The Avengers is a film where I am barely able to conjure any information about.
Maybe it's because I hadn't seen every one of the other films? I just thought the characters were uninteresting, the general plot seemed kind of dull...although I am not entirely sure what the whole point was in the first place. What
was the goal? Loki was going to be King of the World or something? And what about the alien things? Did he do that on purpose, and then wasn't able to control them, or was he controlling them the whole time?
1: Yeah, Loki's goal was pretty much to be the king of the world. Loki's whole deal is that he's deeply insecure and anti-social and he believes that everyone owes him love and respect while he has no idea how to actually get it from people or how to recognize it when he does. He rationalizes this attitude by convincing himself that he needs to force everyone to submit to his will and that he needs to control everyone's lives to fix the world. This is in contrast with The Avengers, who are all just as neurotic as Loki but who recognize that people need to work past their baggage and come together to solve problems. I know I'm making it sound like I think it's the deepest film in the world, and I really don't, it is overall a fairly fluffy adventure, but that is the central theme that connects it all together.
2: As for your question about the aliens, kind of neither? The aliens were his army that he was going to use to conquer the world. He summed them, he was commanding them, and they were doing what he wanted them to do, but he wasn't literally controlling their each and every action with his mind. They were just following general orders.
3: The Avengers left a huge (positive) impact on me. I remember it very vividly.
MOS hit some of my emotional triggers. A lot of people have said it's shallow, and emotionless, but it really worked for me. I do have a tendency to get caught up in things. Like, I have a huge embarrassment squick in films and shows; I don't like to see people humiliated. I also hate to see animals die. Even though I love Fantasia, I can't ever watch the part with the dinosaurs, because it makes me too sad.
I know, I know. I'm ridiculous.
That's something I notice a lot in discussions about this. There are folks who are very deeply moved by seeing a representation of something tragic on screen, and then there are folks (like me) who aren't because they're too aware of the artifice of what they're watching, and they need something else added on top of that to make them forget that artifice.
Could you give me an example of a fight sequence that you feel shows what you mean? I'm not saying that to be snarky, but I still am not sure what you're after. Generally speaking in film, there is hardly ever a concern whether the main character is going to live or not.
A few classic nerd culture examples:
Luke VS. Darth Vader in The Empire Strikes Back. Luke is on the defensive for the entire fight. As Vader deflects everything Luke throws at him and deals back much worse, Luke gets more tired and desperate. By the end, he's exhausted, bloody, and had his hand cut off. And all of this is the physical manifestation of Luke's own struggle to enter adulthood and define himself in the shadow of his father's legacy, and how that turns out to be much harder and much more emotionally harrowing than he was anticipating.
Luke VS. Darth Vader in Return of the Jedi. Luke and Vader both show signs of the fight taking its toll throughout the sequence, and by the end Vader is battered and broken and, in a reverse of the last film, gets his hand cut off by Luke. Luke's anger and ferocity slowly increase as the fight goes on, until he is just wailing on Vader and pounding him into submission, a release of all of the pent up frustration and turmoil that he's had stewing for the past three films.
Buffy VS. Faith in the penultimate episode of Buffy The Vampire Slayer's third season. Buffy and Faith are two former friends, who's friendship ended when Faith betrayed Buffy to the main villains. Furthermore, Faith poisoned Buffy's boyfriend, and Faith's blood is the only antedate for the poison. This fight, the culmination of all of the hurt and resentment that has built up between these characters, is brutal as hell. Buffy is fighting for both the life of the man she loves and to get revenge on the woman who betrayed her trust, and Faith is venting all of her own insecurities and self loathing that she's decided to project onto Buffy since going dark side. This absolutely shows. They throw each other across the room and absolutely nock the **** out of each other. With every blow, there is a very real sense that these two women are fighting with the intent to kill, and one or both of them might die. By the end of the fight, Faith has fallen off of a building with a knife wound in her gut, and Buffy slinks away at a snail's pace with cost and bruises on her face and a nearly broken arm.
This is the kind of thing that makes fights good. This is what creates a real sense of tension and lets us know what exactly is at stake. The Man of Steel fight with Zod didn't have these things, and thus is didn't have any tension.
Oh lord. I can hardly handle the prequels. Is there one particular fight you could recommend so I can try to find it on youtube?
Really, compare any of the prequel duels to the two Luke/Vader duels in the original trilogy. The contrast is glaring on so many levels.
I agree a little blood and wear and tear would have been nice. But I don't find it necessary, particularly since it's a comic book film.
The best comic book fights are the ones that show the toll the battle is taking on the characters. Most of Spider-Man's great fight scenes are like that.
Well, again, most main characters aren't likely to die. So there's not a lot of fear of that happening. I get your point, but unless they are minor characters, where their victory or defeat might serve a purpose in pushing the plot forward, most fight sequences are there to be enjoyed.
1: That is why what I'm talking about is so important. You need to add all of these elements in order to create the illusion that the characters might die. Good storytelling is all about making the audience forget, for a moment, that it's all pretend.
2: If what you're saying is true, then Man of Steel's fight still didn't have any tension, because no CBM fight does.
3: What exactly is there to be enjoyed about a fight sequence besides a sense of tension and what's at stake?
Uhhh, what did the civilians in Avengers do? I don't remember.
During the whole invasion sequence, the film regularly cut to moments where saw all of the destruction and death from the POV of the civilians and really got a sense of their emotional state. There was that whole scene with Cap saving the people in the bank and watching the rescue efforts afterwards.