Yeah, I thought Iron Man 3 had the most exciting and inventive action scenes. Loved Tony and Rhodey running around that mansion, loved the fighting with just the boot and the glove, and really liked the ending with switching from armor to armor (even if it was a few minutes too long)
I found the racetrack scene in Iron Man 2 kind of boring. The suitcase armor was cool looking but it didn't do anything that interesting and the action wasn't that exciting. He just kinda stood there and got choked.