Loved it, loved it, loved it. So much fun. No, it's not the greatest piece of cinema ever, but it might be the best and most genuine comic book movie ever. All of the characters were pitch perfect, and they all got at least one moment in which to shine. I went with my brother-in-law (who's an even bigger comic book geek than I am) and we both had grins on our faces the entire time. This movie deserves every penny it makes.
(some parts in the first act were a little slow and a bit awkward, but that's understandable since there was five movies' worth of setup to get through)