We went to see this movie with friends on a whim, so I really had no anticipation and nearly no expectations - the previews made the movie look like one long explosion. I liked the other two movies, too, but I was very very pleasantly surprised. And yes, there were a lot of cool explosions, too.
In no particular order:
1. The plot was complicated and surprising, but not overwhelmingly so. For an action movie, it was pretty balanced between action and plot (you know, those annoying slow bits with no explosions).
2. The kid. Wow. the perfect combination of innocence with cute chutzpah with just a touch of annoyance and childishness that really made me believe in this character. And I laughed a ton. This kid should get best actor.
3. Non-sugar coating of mental illness. Hopefully it's not too much to give away that Tony Stark suffers from anxiety attacks throughout the film, when he is reminded of some pretty traumatic stuff from The Avengers (like almost dying and stuff). It made him seem more real, more human and down-to-earth that such a cocky and genius super hero like Iron Man could still be psychological effected by all the crazy stuff he has been through. How this character struggled with his anxiety and insomnia I think helps to take away some of the stigma, so we do not see this as weakness, but rather as a sign that he is a normal person reacting to his life.
4. Pepper kicks some bad-guy behind. And I'm not talking about being inside the Iron Man suit (which is like for all of 30 seconds). But I can't say more because it's pretty much essential to the ending. I didn't like that she was a damsel in distress for a while (in a sports bra top) but she did participate in her own rescue (and help save the day).
5. I was shocked to discover that this movie passes the Bechdel Test. The Bechdel Test is an indicator of how well women are represented in a particular movie. It's pretty straightforward - there are three criteria that must be met. A) There is more than one woman who has a speaking role in the film. B) Two of these women have a conversation that C) is not about a man, most likely the male lead. Simple, right? But you would be surprised how many movies are made every year that do not pass this simple test. And, yet, in this film, Pepper DOES have a conversation about Tony with Maya, a scientist/one-night-stand from Tony's past, but later have a conversation about... I can't tell you. More spoilers.
6. The airplane scene. If you've seen it, you know what I'm taking about. I was actually sweating during it, and I don't think I breathed for a full two minutes (or so).
7. The end was pretty epic. And Tony finally gives Pepper a present that she actually loves (again, can't say what - spoilers).
So if you like action flicks, this one is worth seeing. Or at least renting, when it comes out.