'Humans are unruly, and for that reason they cannot be ruled.'

Rating: Null/10 (16 October 2012)

Yes, Stan Lee does have a short 'cameo' role in The Avengers. I re-watched the first 10 or so minutes after I had seen the whole movie, doing so helps put the whole story in perspective.
The USA, NASA, and the World Council are all interested in the small cube of energy captured at one time, it allows a portal to a different part of the universe. When it gets a mind of its own in the lab, the mythical god Loki appears with a giant burst of energy, and right away we see he is up to no good. If he can position the energy cube outside, pointed to the sky, his legions will be able to enter and take over the Earth.
The main star, in a movie filled with stars, is Robert Downey Jr. as Tony Stark and Iron Man. We also have Chris Evans as Steve Rogers and Captain America, Mark Ruffalo as Bruce Banner and The Hulk, Chris Hemsworth as Thor, Loki's brother, Scarlett Johansson (my favorite) as Natasha Romanoff and Black Widow, and Jeremy Renner as Clint Barton and Hawkeye. Tom Hiddleston is good and sinister as Loki.
We eventually find out, after Tony Stark figures it out, that Loki's approach is to alienate each human superhero against the others, divide and conquer. Humans are eventually saved when the six superheros band together and each uses his and her special powers to defeat the aliens.
Of course there is lots of action, much of it taking place on a very large aircraft carrier that can transform itself into a giant flying carrier. Then the final action is in Manhattan, with quite a bit of destruction. In the end it is Stark as Iron Man that diverts a missile with a nuclear warhead, steering it through the upper opening of the portal, destroying the mothership which was responsible for keeping the battle going.
Other key characters were Clark Gregg as Agent Phil Coulson, pretty Cobie Smulders dressed in a sleek black outfit as Agent Maria Hill, Stellan Skarsgård as the scientist Selvig, Samuel L. Jackson as facility head Nick Fury, and Gwyneth Paltrow back as Stark's girl Friday, Pepper Potts .
Overall a fine action comic book movie.