Visually, it's as beautiful as any of the other Marvel movies made recently. Say what you want about the lack of development in most of them, but they're gorgeous in terms of eye candy. The desert is bleak, the armor sleek, and the city is practically luminescent.
The audio is divine. Especially at a theatre like the Carmike 12, which features a wicked sound system. The sound of the explosions, gunfire, and footfalls of the larger armors are visceral. You feel them every bit as much as you hear them. The soundtrack is similar, built upon heavy guitars. Thankfully, the movie utilizes, but didn't lean on the Black Sabbath track that the character was named for. Keep this movie in mind when you upgrade your home theatre, this will be the movie that you want to demo on the sound system.
The story is well written, and does a good job of modernizing the origin of Iron Man, taking the setting from the Vietnam War, to the current OEF.
What really sets this movie apart from the other superhero movies is the acting. At first, I was opposed to the idea of Robert Downey Jr. playing Tony Stark. However, the more I thought about it, Tony Stark is essentially a womanizing drunk, encased in a flying tank. Robert Downey is already a womanizing drunk, and the flying tank is just special effects. He acts out Stark with the natural finesse of a man who isn't really acting. Gweneth Paltrow is stunningly beautiful in the role of Pepper Potts, resilient, yet still very feminine. Terrance Howard plays Arthur Rhodes a little softer than he's portrayed in the comics, but he does a very good job at operating as a foil to the more flamboyant Stark. But in my humble opinion, the most underrated performance was Jeff Bridges' portrayal of Obadiah Stane, easily the most complex character in the film. All these actors are stars in their own right, but the synergy they achieve in the film is amazing.
One quick note for when you watch this film, when you watch the ambush, keep in mind that it's the Air Force trying to defend Stark. They are flyboys, and not indicative of the military at large. They certainly aren't infantry. They did just about everything possible wrong in terms of defending against an ambush. You could take pretty much any buck private from my company and they'd do a thousand times better than the flyboys in the movie.
All in all, this is the most entertaining film I've seen in at least a year. I think There Will be Blood and Juno were fundamentally better films, but not near as fun to watch. There's something for everyone in this film. It possesses a rare mix of comedy, action, and drama, without overdoing it. And if you stick around after the credits, you'll get another gift.
Go see this film, you will not be disappointed.