Re: Worst Marvel Studio's movie so far?
IM2 for me. I'd echo those who have said that its not a bad movie, but it just had so much potential that it didn't live up to. I really liked the ideas presented in it such as Stark's story arc, as well as the way it reimagined Whiplash and Justin Hammer. But by that same token, Stark's story lacked weight, Whiplash was underdeveloped, and Hammer should've been written a bit more seriously.
Thor would probably be my other least favorite. I think it's a better movie than IM2, but it didn't leave much of an impression on me. Though I am hoping to get a chance to watch it again soon, so maybe it'll click better with me.