My expectations for the movie were somewhat tempered by a review or two from sources such as Variety and Newsarama.com, so I wasn't too surprised by the fact that I enjoyed the movie a great deal. That's sort of been the consensus.
Iron Man is a movie with one foot in fantasy, from the science-fiction of the armor and Tony Stark's household futuristic technology to the idealistic method in which Stark is able to redress his moral failings. The other (much smaller) foot is placed in the reality of the sort of combat our soldiers are facing overseas, and the responsibilities of folks buying yachts off the proceeds from the sale of scud missles.
The effects in Iron Man benefit from the fact that the armor is non-organic and there's no fear of the Uncanny Valley. Seeing the trailer for The Incredible Hulk, just minutes before Iron Man rolled, reminded me that despite the fact that I have no idea what an 8-foot green giant looks like, I can still look at CG-Ferrigno and know that I'm watching a nicely animated cartoon. Not so much here.
There's a lot of good stuff in Iron Man, and more than being a movie about two mad scientists duking it out, or a mad scientist and Afghani boogey-men, its much more about discovery of self and super-science development. And, kids, those scenes are a lot of fun to watch.
The talent in Iron Man is actually very impressive. Paltrow's Pepper Potts refuses to be another Mary Jane in distress. Jeff Bridges is more than a cackling villain, though the script does point him in some mad-sciencey, hand-wringing directions. Terrence Howard is a good James Rhodes, but you sort of hope he gets to suit up in Iron Man II.

And Robert Downey Jr.? For all the cliches of the movie, Downey makes you forget you've seen this movie before in bits and pieces. His Stark is not the boring guy with the mustache who kept me from reading Iron Man in middle school (alcohol problems or no). He's a guy who has already found his place in the world, he's succeeded in the ways of the American Dream, through hard work and brilliance, and he's enjoying the hell out of it. Unlike movies like Spider-Man, which show us a character in the transition of youth, we get a fully formed character with whom we get to see the exact why's and how's of their change of heart. And, maybe, being a few years out of high school, I'm relating a bit better to Tony Stark these days than Spidey. Although, you know, without the billions and genius.
Many will find Stark's moral awakening to be a contrivance, and somewhat childish. After all, blowing people up should be considered patriotic. But I found the reasons for the awakening to be plausible beyond just the confines of the story, and possibly asking some questions that Americans assume are usually taken care of, but... you know...
Anyhow, this is seriously one of the most fun superhero movies Marvel has managed to put out in a long time. Where Spidey 3 disappointed last summer, Ghost Rider utterly failed, and Fantastic Four went to the negative zone, Iron Man was a great ride.
I'm finding I'm enjoying superhero movies MORE when I don't know too much about the characters (or, like Superman Returns, its such a departure, I have nothing to compare it to). So I get the cool superhero action (and the action in this movie is pretty good), but I also don't spend the movie figuring out how this is different from the comic.
I'm looking forward to any potential sequels. And I may give this one another round before it leaves the theaters. Kids will want their Iron Man suit this Halloween. Adults will wish they could find a way to test drive the suit and have Stark's home management system.
Oh, and nerds will want to wait through the credits for the final scene of the movie. Oh, yes. You will want to stay.