Seen: The Avengers (2012)
Well, it's entertaining, and the characters established in all those movies have real chemistry together, especially between anybody and Tony Stark (Robert Downey Jr) who manages to get on everybody's nerves in his endearing way. The characters we've seen before are much as we've seen them before; only Clint Barton (Jeremy Renner) is new to us, and manages to be kind of a nonentity among all the more spectacular heroes. Which, come to think of it, Hawkeye always was in the Avengers comics. Chris Evans has settled into the Captain America role and gets some good mileage out of having slept for seventy years. Samuel L. Jackson is back as Nick Fury of SHIELD, complete with helicarrier and Council. And Mark Ruffalo is the best Bruce Banner ever.
But the real delight is Tom Hiddleston's Loki. Where he was a bit shaky in the Thor film, he's spot-on in this. And don't we really watch superhero movies for the villains more than the heroes? (Well, except for the Iron Man films, where the heroes are pretty boring but the hero is fun.) (Speaking of villains, there's a great reveal (for Marvel fans, anyway) in the first Easter egg. There are two, one in the middle of the credits and one at the end.)
One thing that's brushed over is that a lot of people must die in the climactic battle, but that's never mentioned. Massive parts of New York are destroyed, by aliens and heroes both. The Avengers find themselves as a team. Tony Stark finds his inner hero. It's good fun.
One should probably say something about the special effects, but at this point who cares?