The first "post-Avengers" film from Marvel Studios (another Thor movie is on the way later this year, as well as another Hugh Jackman "Wolverine" picture) features Tony Stark/Iron Man (Robert Downey Jr.) dealing with the events of New York City, in which the Avengers repelled an alien invasion. Stark was so traumatized by the events that even the mere mention of the words "New York" sends him into a panic attack. He finds comfort in designing new iron man suits (of which there are many), but girlfriend Pepper Potts (Paltrow) can only be ignored for so long. Suddenly, there is a new threat to the world in the form of Mandarin (Ben Kingsley), a terrorist of "Bane"-like proportions. Mandarin seems to control an army of super-powered soldiers who can generate some sort of intense thermal heat within their bodies (their powers include super-strength, speed and regeneration). It's quite an intense challenge, to say the least.
If there's one thing these Iron Man films have in common, it's that Tony Stark has been more interesting outside of the armor than in it, and the build up to the big, computer-effects driven fight scenes is more entertaining the the fight scenes themselves. This, perhaps more than anything, exemplifies "Iron Man 3", where the climactic battle is a little underwhelming when compared to the journey to that point. Well, there's another thing these Iron Man films have in common (so it's two things), and that's humor. This might be the funniest and fun-est of the three films, and there are several "wtf" moments where it's clear this film doesn't take itself very seriously (as opposed to something like, I don't know... "The Dark Knight Rises"). And really, I have to think Mandarin is a little jab at Bane, and the Dark Knight Rises in general. Look, you liked Iron Man and Iron Man 2, you will probably like Iron Man 3. There aren't any major deviations from the others. It's a good, fun action movie.