This time, Loki (Tom Hiddleston) wants revenge for his banishment by his brother Thor (Chris Hemsworth) by taking over the Earth realm. With the help of an alien race, Loki goes after the Tesseract, a dangerous energy cube that could destroy the entire planet alone. So now Nick Fury (Samuel L. Jackson) must once again attempt to assemble the Avengers to help stop him. They go for the wisecracking genius with a suit of armor, Tony Stark/Iron Man (Robert Downey Jr.); the super-human soldier from the past, Steve Rogers/Captain America (Chris Evans); the gamma-radiated scientist who might be the only one who could find the stolen tesseract, Bruce Banner/Hulk (Mark Ruffalo); and then include his own agents, the Natasha Romanoff/Black Widow (Scarlett Johansson), Phil Coulson (Clark Gregg), Maria Hill (Cobie Smulders), and Clint Barton/Hawkeye (Jeremy Renner).
The biggest question of everyone's minds was... how can Joss Whedon pull off such an ensemble cast battling for screen time? Surely some were going to be left out more or left underdeveloped; he couldn't possibly give equal time to all of these characters and still have a good and/or cohesive film. But I guess these people don't watch a lot of Whedon, because thats basically one of the things he does best. While I was watching, I kept wanting to say "Oh, RDJ is stealing this movie." But then 10 seconds later, it'd be like "Oh, The Hulk is stealing this movie" and then "Oh, Scarlett Johansson is awesome in this," etc. Of course, Whedon's not a moron. He played up fan favorite Tony Stark, giving him some of the best lines. Everybody has their highlights in this movie, though. Jeremy Renner comes closest to being left behind, but the reason is pretty obvious--he's the least known of the bunch. He builds him up just enough to keep an interest in him and make him cool, but Whedon doesn't put a ton of focus on him; he keeps that on the characters the mainstream audience actually already know and want to see. The biggest surprise, though? The Hulk. After two incarnations on the big screen (one terrible, the other decent), I think Whedon finally hit the nail on the head. Ruffalo's Banner is solid, and the Hulk itself looks good and has some fantastic moments in the third act (actually, he probably has the two of the best moments in the entire movie).
Speaking of the third act... has that not been the bane of the pre-Avenger movies' existences? It seemed every time, we were all left underwhelmed by the "final boss battles." There was all the build up and then... short and not very exciting. But not this time. The third act is fantastic. The city-wide battle is outstanding, and Whedon makes sure every character has at least two or three moments to really shine. And yes, the final fight against Loki himself might be incredibly short, but it's easily one of the greatest moments in the entire film. I don't think there was a single person in the audience who wasn't laughing and cheering at that moment. Simply fantastic.
Outside the wonderful action sequences (mostly in the second half of the film), there's a good mix of comedy and drama. And just like with the action, everyone gets a turn. There's the rivalry between Tony Stark and Steve Rogers; the bond between Black Widow and Hawkeye; the isolation and worry of Bruce Banner; the trusting of Thor amongst the Avengers themselves, as well as the relationship between Thor and Loki; and, of course, Agent Coulson just being the scene stealer that he is. Of course, at the same time, the scenes in between the action can be a bit slow at times, but the ones that drag never linger too long before something strikes your fancy.
So in the end, I think it really worked. I saw it with a few other people, one of which hadn't seen any of the Pre-Avengers flicks, and he still really liked the movie. So I guess prior viewing doesn't necessarily matter, but I'm sure it definitely helps some of the deeper understandings of the characters and their past relationships with others. If you want to see a great comic book movie with awesome action and some nice comedy, check this out (if you haven't already). As a side note, I also saw this in 3D. It didn't hinder the movie whatsoever, but it's not totally necessary, either. It's, again, one of the more atmospheric types. So if you're wondering whether to see it in 2D or 3D, it doesn't matter one way or the other. The 3D won't hurt your experience, but it's not gonna blow you away, either. Anyway, I had a really great time with this, and I'm definitely going to check it out again.

Royale With Cheese
(P.S. Make sure you stay after the credits! There's a scene about halfway through and another at the very end. The one halfway through is a sequel hint, and the one at the end is just comedic.)