This is the best of the Iron Man movies. I remember when all the reviewers were saying the origional iron man was amazing. I saw the first Iron Man, and thought it was good, but not as great as so many people made it out to be (I did not enjoy iron man 2).
In this film, Iron Man faces off against a shadowy organization connected to his past. It caused a great deal of controversy because the character of the Madarin is nothing like his comic book counterpart. This disappointed a lot of people because the Madarin is considered to be Iron Man's most famous foes.
What makes this movie the best Iron Man film, is that Tony Stark spends most of this movie without his armor. The second half of this movie is actually more like a James Bond film than a super hero film, but that a good thing. Too often super heroes become more powerful and face stronger foes in their sequels. In this film, Tony Stark is weaker than he has ever been, and that just adds to the suspense.