I like em all, but I feel like 2 gets mistaken for a bad movie. Its poor compared to the better MCU movies, but its a decent action movie by itself.
It's an OK, but extremely flawed movie. The biggest issues with Iron Man 2 is its pace, lack of villain expansion, plot holes, bit of filler, and large plate to cover for 2 hour timeframe. Often times I would watch Iron Man 2 and say "What? Why would they put that type of content in it when X would be more effective?". Scenes like when Hammer helps Rhodey to equip the Mark 2 suit with weaponry was useless, rather they could have spent more time Ivan or whatever his name was. Same goes for the scene where Ivan has a meal with Hammer. They could have developed a much better arc without Ivan himself. Also what was with the whole Tony dying to his arc becoming less effective arc? That was totally useless. The best superhero movies gives the same amount of attention to the antagonist as they do to the protagonist. Then they had to set up SHIELD for The Avengers, which brought its own arc. Pretty sure Jon Favreau had less creative control as the result of this, as it shows that if he DOES get control, the movies he can make are great (Chef, Jungle Book, etc).
Can't deny the action scenes were fun as hell though, but it was just a passable film compared to the first Iron Man. Don't understand the argument (if its presented) that it's supposed to be a popcorn/fun movie (ala Suicide Squad or Fast 7). I don't go to the movie theater to watch something mindlessly, I enjoy understanding the characters' motives and how that can impact the narrative.