Before I get started, I liked the movie, but I wouldn't give it any higher than a low B, and that might change after I see it again.
The first half was really boring and dragged on. I didn't feel like anything was happening. Also the dialog was way to "Whedony." I got tired of Tony's witty retorts fast, and when Thor did it, it was painful. Cap's lines were pretty great. The movie emotionally resonated with me, though, and the second half was phenomenal. If it weren't for the boring first half and Whedon trying to hard, it would have been great.