Iron Man 2 is boring and many things went wrong.
Its main problem is the villain: you cannot build up a villain such as Whiplash with Mickey Rourke and have him doing nothing during all the movie. And with no villain doing anything interesting - Sam Rockwell as Justin Hammer was barely the comedic relief, no more than an enabler - the hero doesn't have much to do either: all that happened was Tony Stark fighting drunk with his pal - and we all knew nobody was in real danger there - and profuse introduction of the upcoming Avengers movie's characters. The plot about Tony dying got diluted in this narrative void.
As for second parts, it's the least favorite of mine:
The Dark Knight
Iron Man 2
Originally Posted by Steamteck
This discussion about Natasha being useless has made me want to see Iron Man 2 again mainly for her scenes. I liked her character in the movie. I thought she was interesting had personality and served a purpose both narratively and given a varied type of action.
I can't see a vital purpose for her in the movie; nothing that was ultimately necessary. It wasn't until Avengers that she really shined.