I went to go see it at noon today, with no expectations at all. I haven't read any of the comics, and I hadn't seen much about the movie, save a couple commercials, and needless to say, I was pleasantly surprised. The movie was hilarious, inventive, visually stunning, and was just overall amazing. It was so good that I went to see it again at 6:45. If I didn't have to work in about six hours, I would have seen it another time. I just can't get enough of it!
PS - If you go see it, be sure to stay after the credits.
PPS - Robert Downey Jr is not only a great actor, but he also has a HOTTT ass!