Nick R’s review published on Letterboxd:
The Avengers (all right "Avengers Assemble" if you insist) really is extraordinarily good. It's pretty much everything that's fun about superhero comics translated directly onto the screen - I was hoping for as much from Joss Whedon and he delivered.
Like Serenity and the Buffy season 5 finale, it's extremely well-structured so that everyone gets more than one moment to shine in both dialogue and action scenes; I can't think of another action movie that has so many characters and is so well-balanced between them all, and all the different combinations of arguments and team-ups between them.
It's also extremely funny (but mostly not in that trademark Joss Whedon "Buffyspeak" way that some VERY WRONG people find "precious" and annoying). It has better Tony Stark dialogue than either Iron Man movie! Having said that, the funniest gags are visual ones that involve the Hulk...
I often complain that superhero films' weakest parts tend to be their climactic action sequences: the stakes are raised, and believability is strained. As a rule of thumb, the closer to Armaggedon a superhero film's climax gets compared to the preceding parts of the movie, the more disappointing it'll be. Well, for once we have a superhero film whose best action scene comes at the end! It's one of the best-sustained action finales since The Matrix, constantly spectacular and containing countless satisfying moments in both action and dialogue - most of which also happen to be very funny. The constant barrage of events means that spectacular actions that would have been highlights of these superheroes' individual films are easily forgotten amidst the rush of even better actions. And yet it's all presented in a coherent way, with the geography of the battlefield remaining clear throughout - there are none of the incomprehensible shakycam shots that spoiled The Dark Knight's action scenes.
And that's just the third act action finale! The big mid-film action sequence, which splits up the characters into pairs, is almost equally good.
However, the best single scene in the whole film isn't an action scene. A standard phrase Joss Whedon has used in promotional interviews is "I wanted to figure out why all these different characters should even be in the same room as each other". Well, that scene where they are all in the same room as each other turned out to be the film's absolute highlight. There have been lots of action films that I've enjoyed at the cinema for their sheer spectacle but then have felt little desire to rewatch because that they didn't have much else going for them (Avatar comes to mind) - but due to scenes like that, The Avengers isn't one of them.
The film's plot isn't exactly intricate: it's extremely tightly focused around the MacGuffin from Thor and Captain America. However, this isn't a bad thing: in a film of this scale, ensuring the characterisation and action is satisfying is an ambitious balancing act as it is, without adding a complex plot as chaotic as that of The Dark Knight into the mix as well.
The film doesn't carry any sort of larger real-world message; it's really just a movie about these specific characters - about guys in silly costumes beating the crap out of each other. But as far as movies about guys in silly costumes beating the crap out of each other go... well, it's hard to imagine how they could get much better.