Sometimes, it's easy being me. I'm not one of those cult movie fans always in desperate need to proof they're part of the cool kids (not unlike certain friends of art movies who would not be found dead ever being entertained by a movie, or smiling watching one), so I can allow myself to like those blockbuster concoctions that are good, or - as is the case here - pretty fucking great.
Given the overabundance of money director/writer/king of nerds Joss Whedon had to blow up (often quite literally,) it's not much of a surprise The Avengers' spectacle is fantastic to watch. Although even that part is not always a given if one keeps the body of work of Michael Bay in mind, who knows how to make big explosions and giant robots boring. Whedon, on the other hand, knows how to make the big and loud things big and loud and actually interesting.
Not surprisingly, he also understands that the big and loud things become inherently more interesting, more fun and more important to an audience if you anchor them in smaller and quieter moments that are in reality much more important, and therefore spends as much - if not more - time and effort on these.
As an old comic fan, Whedon also inherently gets what his characters are about (so no Bendis-style Captain America silently condoning torture, and no Kenneth Brannagh-Thor as a jock with a hammer), and uses this knowledge, a cast that can act their asses off if given the opportunity (and isn't by the way, Mark Ruffalo the best Bruce Banner you've seen, and Scarlett Johansson a much more convincing Black Widow than anyone could have expected?), and a script that manages to squeeze an insane amount of subtlety in to make what would in a lesser movie be just the connecting tissue between action scenes sing.
Other typical Whedon virtues are also in and accounted for - the quick and clever dialogue, the sudden reversals of genre tropes, and the ability to naturally shift from comedy to tragedy and back again in the course of two lines of dialogue. The real beauty of the film is how well this aspect of The Avengers connects with the more usual blockbuster virtues, as if having a heart and a brain and big explosions in a movie wasn't a big thing.