That was as good as the trailers promised. It may in fact be my favorite superhero movie ever. And I include both The Incredibles and Batman Mask of the Phantasm in that calculation.
Stay until the end... the post-credit teaser is great.
Just a great, fun movie that is laugh out loud funny but doesn't make fun of superheroes, has great action, great characters, great acting... Favreau has just showed everybody how it's done and raised the bar. Give that man a blank checkbook and let him make the Avengers movie.