Iron Man is really good. I would definitely recommend it.

It had the right amount of backstory, action and humor. Downey is the perfect Stark and Jeff Bridges is very good. I can't stand Paltrow, but she was not a problem for the film. Her witty banter with Downey works well without being overdone. The fight at the end could have been better, but this thing more than holds its own with the best movies this genre has to offer.
Important Note: Stay for all of the end credits. There is a scene at the end of the credits that is very cool and gives a glimpse of the future for Iron Man. Don't miss it.
On a final note, the new/final The Dark Knight trailer played before the film as did the new/final The Incredible Hulk trailer and the new/final Indiana Jones and the Kingdom of the Crystal Skull trailer. Of course, there may be a different set of trailers depending on where and what theater you go to see Iron Man. I know people who went to Iron Man tonight and didn't see all three of the trailers that I did. You can pretty much expect to see at least the Hulk trailer since it is another Marvel property.
