As someone once told me and these were my exact sentiments, "Dark Knight worked so hard to be realistic and serious, that it forgot to be fun". I've had a lot of fun watching Iron Man 1 & 2.
Well, I know who said that and I have to say I totally disagree with both of you. TDK did a fantastic job of blending being serious/realistic which is more the niche for Batman. He's a dark character with lots of issues as a person that he's trying to make up for with some enemies that have dark backgrounds. I had a lot of fun watching TDK and do every time I plop in my blu ray.
The Iron Man films are totally different. Different character with issues but done in a different way. They aren't approaching it the same way though they did a bit in 2. All while at the same time being a crap load of fun.
I wonder outloud how much of this is a DC vs Marvel dislike type thing? As someone who is just a fan of both I will say I like Iron Man more than Batman and like the Iron Man series more than the Batman series. I enjoy both for being what they are awesome films, which are fun, serious, and a good ride.