Spoiler: There isn't much.
I'm not sure if I'm ready to stick Joss Whedon's Marvel's The Avengers at the top of my favorite based-on-a-comic-book movies or even at the #1 superhero movie spot (although it's damn near). It would have to share space with the first Superman movie (largely on Reeves' perfect nailing of Supes, and nostalgia), the second Spider-Man movie (great themes, the first perfect superhero movie fight scene, my love for Spidey), the second X-Men movie (better script, better acting, Nightcrawler), the first Iron Man movie (almost flawless) and Batman Begins (first version of Batman that villains might actually fear).
But it was far and away the most fun I've had in a movie theater in a very, very long time.
So why pick on it? Well, my love for Whedon is well-known. Many excellent reviews and essays have already been written — check FilmCriticHulk, and theonetrueb!X's look at sentiment as a theme — and I'm sure PopMatters is already gearing up for a collection. But I'm known for my amateur script-doctoring, so my self-appointed, unrequested task is to analyze this movie and see how it could have been improved, in my own unfair and uninformed way.
MAJOR SPOILERS ahead, probably, for those ten or twenty unfortunate people who were in a coma over the weekend and therefore did not see the movie. Doctors are, even now, feverishly working on ways to pipe The Avengers directly into their brains.
WHAT WAS WRONG WITH THE AVENGERS MOVIE
2. I'm thinking…
3. Oh! Here's one! How come it took days and days for Tony Stark to plummet from his tower, leaving his VII armor plenty of time to zoom after him and encant him, but the letters that got knocked off the same tower during the Loki-Thor fight hit the ground almost immediately. There's this experiment with differently-weighted falling things, see…
UPDATE: Answered in the comments. The letters didn't fall to the ground, but to a nearby rooftop. Fair enough.
4. Yeah, that was movie-time and not really a deal-breaker. Give me a few minutes.
5. The Galaga scene on the helicarrier. Yes, it was funny, but it was a bit too obvious. It's across his whole frickin' screen! How could anyone NOT have noticed that? I'd have preferred a more subtle version, with his Galaga-playing almost hidden among a sea of different windows and apps, with only the quiet music to tip off the observant viewer. (Also, the sound effect was wrong for the action, so, you know, that.)
6. Banner in India. The movie has already gotten some flack for the repetition of the If-you-want-slums-you-want-India trope, and frankly it deserved it. How about Sub-Saharan Africa, or Somalia? Even the second Hulk movie ended with Banner in British Columbia.
7. Hawkeye's bow. I'm sorry, there's no way a bow with any power at all can be "snapped" from folded to full-length. I kept thinking he was fighting with a Nerf Bow. Which, granted, would have been awesome.
8. Captain America's helmet. The WWII one was better. He's a soldier, dress him like one.
9. The attacking army. Which was not so much. I mean, yes, there were hundreds dropping through the big floaty hole, but I expected thousands just pouring out of there. Maybe the LotR movies have spoiled me, but when I hear "army" I think masses, waves of warriors. And they weren't so much an army as a marauding force. They didn't seem to have any tactics other than "shoot stuff."
Which was understandable, since no one was leading them. I thought that was Loki's role, but even after he got away from Thor he didn't do anything leadery. Might have been nice to see him try to direct the battle, only to find out there wasn't actually anything under his control, foreshadowing the stinger scene later on.
10. The resistance. There wasn't one. I'll grudgingly accept the lack of military presence — there were tanks, eventually, and one nuke-carrying jet, so maybe the shadowy council nixed the idea? — but no New Yorkers took any swings at invading aliens? Really? Have you been to New York? I'd rather have seen some indication of a civilian resistance that Cap could have guided before going back to the super stuff.
11. The big floaty snake things. I guess these were troop carriers? And we saw, as they went down, they were capable of a great deal of destruction, but before that they were mostly galumphing past for the heros to beat on. They should have had a clear agenda for the heroes to thwart.
12. The waiting army. When Stark flew the nuke through the portal, there should have been thousands, hundreds of thousands, of warriors waiting. The Earth should have been in dire danger of being swarmed. It should have made the audience gasp. Instead there were a dozen or fewer ships, with a big mothership thing in the distance. Ehh.
13. The 3D. I'm not a fan of 3D but I heard good things about this one, so, after seeing it in 2D first, I went back and ponied up the dough for my cheap glasses. It was… OK. I was impressed when it worked, which was a lot of the time. But the final battle looked worse, I thought. The flying warriors looked even more CGIish, and it was more difficult to make out what was happening. I think it's because in an active scene like that, the movie's choices as to what's in focus and what is not is just different enough from what I would naturally be focusing on made it jarring.
14. The death. You know the one I mean. I don't actually have a problem with this one on its own merits. Coulson's death makes sense in the situation (a guy against a god), it makes sense thematically, and it serves a purpose to the plot while giving him some good lines to go out on. But as part of Whedon's oeuvre it's getting too predictable, and he needs to start paying attention to that before it becomes too much of a joke, like M. Night Shyamalan's plot twists.
And that's pretty much it, really. The first hour dragged a bit with the necessary exposition, but I don't think there was a solid five minutes anywhere in the movie that didn't have something cool in it. Everyone got not one but several hero moments, with the Hulk getting even more (which makes sense, he's bigger). I can't count the number of ways Hulk was handled correctly, from the humor to the motion-capture to the easily-discernable Mark Ruffalo features to the pudginess. He was pudgy! And had chest hair! And a personality! And yet somehow looked more menacing than the weight-lifter cut of the first two movie Hulks. Oh, the humor and the action and the teamwork at the end and Black Widow and Steve Rogers vs Tony Stark and and and…
If it's not clear, I love this movie to an absurd degree and plan to see it again in the theater a few more times. Doesn't mean I can't poke at it…