Captain America in the classic WW2 style.
It’s all about the characters.
A well told story tells you a whole lot with very little. A few moments, a few lines, a few sketches of their history and hints at their future and the audience begins to believe that they know them.
In “The Avengers” not only does each character get his/her moment in the spotlight, but each one is distinct, defined and interesting.
Black Widow is in control (or is she?), Bruce Banner is a ticking time bomb, Captain America is everything good from the Greatest Generation and Iron Man is a punk-ass playboy, and each one says so… literally. So much characterization delivered in so few words is truly a thing of beauty.
Power is central to a comic book character’s success. It defines who they are and what they can do. And, more often than not, it gets way out of control.
Characters can easily become so powerful they become boring and indistinguishable. Maintaining a story where there are “levels of power” (i.e. this thing is more powerful than that thing) is critical to making team-oriented stories work. If someone can never be defeated then there’s never any “real” jeopardy they can be in, which means the audience can easily tune out.
“The Avengers” keeps everyone’s powers in balance. In a movie where everyone can be the best, not everyone is. In a movie where everyone can be a god, not everyone is. Some people were strong, others were stronger and a few were the strongest. And everyone’s individual strengths remained distinct.