Iron Man 1 - okay
Iron Man 2 - eh, okay
Iron Man 3 - Awesome!
Need I say more?
I loved it! It's not very often that a sequel, let alone number three, is better than the first one. In fact it's very rare. Iron Man 3 is one of those sequels.
The only other franchises I can say I liked the sequels even better than the first are Charlie's Angels (love Full Throttle) and Terminator (the second one, Judgement Day is the best in my opinion.) Also, Iron Man 3 had the best ending credits since Ferris Bueller.
I loved the mix of action, comedy and drama in Iron Man 3. I thought it had a solid story. I've always loved Robert Downey Jr. and think that his Tony Stark is genius. I'm a comic book reader, however I will confess that I never read Iron Man, so I've had nothing to base the character on.
I'm obviously not the only one who loved it. As of September 5th Iron Man 3 grossed over 400 million dollars (worldwide over a billion) and is ranked 4th in superhero movies after The Avengers, The Dark Night and The Dark Night Rises. It's followed by the 2002 Spiderman in 5th place.
(Statistics from Box Office Mojo.)