Okay, I am going to say it, as a stand-alone movie, Iron Man 2 wasn't that good.
It set up beautifully Thor, Captain America and The Avengers, and Robert Downy Jr. was fantastic. But it spent so much time introducing Howard Stark, Black Widow, Ivan Vanko and Justin Hammer and getting us use to the new Rhodie that Tony Stark, Pepper Potts and Happy Hogan became background characters.
To screw up the story even more they have to bring in a plot from Atlas Shrugged. Now, I have not seen Atlas Shrugged part 1 (And why are they making a sequel? That movie only made less than a quarter of the budget. Still, far better than A Troll in Central Park. Oh wait, this is made by the same people who don't understand budgets; conservative Republicans. Never mind.) Nor do I want to subject myself to that divorce from human reality. It's a book the National Review, yes, THE National Review, called "a book that no sensible adult could take seriously."
And for some reason Jon Favreau decided that he would cram Atlas Shrugged in the middle of Iron Man taking on Bullwhip who then reinvents himself as Crimsom Dynamo. I didn't have a problem with the fact he took 2 characters nobody really cares about and tried to make them into something compelling. I was upset that I paid money to see a film with Bill O'Reilly in it. That means my money went to that rape justifying, accomplice to murder, cop briber.
And then there is the "friendship blast" at the end. A plot device used in defeating evil on "My Little Pony." (Okay I have no clue if they ever used it on My Little Pony, but I am sure it is a safe bet.)
The best part was the guy behind me at the theater. When my freinds and I stuck around for the last scene, which reveaed a (Spoiler allert) hammer, the guy behind me errupts, "A F***ing hammer? I stayed through the ending credits for a F***ing hammer?" One of his friends tried to calm him down, by saying "It's Thor's hammer." He turned to his friend and said "Who the F*** is Thor?" THAT is what made the movie for me.