The Avengers was a great movie. While excessive descriptors are sure to come, this essential truth might be loss. The Avengers is an action movie, thus it suffers from its summer movie mass audience mission. Yes, the Avengers has massive special effects, and unlike some recent 3D efforts, I think the Avengers used the 3D for the benefit of the film, not simply to drive up ticket prices. Yes, the film has great cast. The actors did an excellent job, Robert Downey, Jr. has found his stride as Tony Stark/Iron Man, and I think Scarlett Johansson really evolved the Black Widow as a character. Mark Ruffalo' Bruce Banner/ Hulk provide a nice counterpoint to Tony Stark/Iron Man and Whedon smartly put the two together. Jeremy Renner did a great job as Agent Barton (never really got called Hawkeye...exactly. Like much of the Marvel Cinematic Universe, his take on Hawkeye has more to do with Marvel Ultimate Comics than the classic Silver Age Marvel, but that point is more for comic fans (and scholar like me) than the general audience. They got a solid performance and great new character. The performances all around were solid, small supporting part and large provide a real and engaging cinematic experience.
All these points you will here, but perhaps the accomplishment of making all the moving part work might get loss. What Joss Whedon accomplished with the Avengers was to create a solid, well balance film that entertains the audience. If you do not know Marvel Comics, it doesn't matter. If you do know the characters' long history the film is especially rewarding. Whedon has a talent for finding the individual character moments in a big ensemble, and he does this to great effect in the Avengers. Whether it is action sequence or dialogue exchange, when the character take action, it makes sense. The emotional gratification the audience gets when "Hulk smash" isn't simply about the CGI accomplishment, its about the commitment to a cause (the smashing being awesome is a bonus:-)
Given the nature of the film, its unlikely Joss Whedon will get the kind of auteur praise that Christopher Nolan is sure to receive for the Dark Knight Rises. It is a shame because, like Nolan, Whedon has understood the source material, crafted an engaging cinematic vision and produced a wonderful film. The Avengers is already a global financial success, Whedon has done something for Marvel Studio pivotal for it next cycle of films. He has created a benchmark experience that connects all the previous film and solidify the Marvel Cinematic Universe. From these efforts, we will want to see what happens to Iron Man, Captain America, Thor and all the rest.