It took quite some time for me to enjoy both of the "Iron Man" sequels, and to this day, I still think the first is the best. I remember seeing the second film, not really understanding most of it, then buying the Blu-Ray and still being unable to keep up all the way in my head. About a year later, I finally watched it again, and was surprised at how much it suddenly made sense. My only gripe is that Whiplash's final fight was too short, though seeing Tony & Rhodey battle "Hammeroids" together was sweet.
Like many fans, I despised what Shane Black and Kevin Feige did to the Mandarin in "Iron Man 3", and it still makes me cringe a bit. On the whole though, I enjoyed it much more the second time around. I'm hoping they make a fourth one with Robert and Gwyneth, or at least have Tony pass the armor to someone else in one of the "Avengers" sequels.
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God, guns, and guts made America; let's keep all three.