As usual, I'm late to the discussion, but having finally caught Iron Man yesterday, I'd posit that it's one of the three best superhero movies ever made. (The other two, for my money, being Spider-Man 2 and Batman. I won't count The Incredibles, but if I did, that would make the list, too.)
In fact, I'd call Iron Man a nearly perfect movie in every way. Like with the X-Men franchise, the production benefits from having a seriously great actor in the lead. The effects are so top notch that they didn't even particularly register as CGI (for men, at least). But most importantly, the script accomplishes a number of very difficult tasks with much grace:
* Like Superman, the character of Iron Man suffers from near invulverability--particularly in his current incarnation. The story very deftly and believably creates a conflict in which Iron Man is quite vulnerable.
* The script keeps the stakes at a reasonable level--the fate of the world does not hang in the balance--but still keeps the conflict very interesting.
* One of the problems with origin movies is balancing back story with forward progress. This is doubly true with Iron Man since his back story is just well known enough to be cumbersome, but not well known enough that it can be glossed over. By started in the desert with Tony Stark's capture, getting that out of the way in about 2 minutes, and then jumping backwards in time, the script gives Tony's back story more time to play before the audience needs it to move along.
* And the big payoff for this is that we get to see Robert Downey Jr. at his most charming. Tony in Vegas is pretty irresistible and we get to see just enough of him as a cad. When he has his epiphany--which the script seems to earn pretty nicely--he's able to keep the charm of his caddish behavior even as he's losing the narcissism. That's an awfully fine line to walk, but the writers did balanced it perfectly.
* Finally, the script handles Obadiah Stane perfectly. It's not clear if this is the Obadiah from the normal Marvel universe or the Ultimate universe. (One of the really interesting thing about Marvel Studios is that it seems to be creating a third stand-alone universe, melding bits and pieces of the other two.) The problem with Obadiah is that he's obviously the villain from the moment we first see him. But the script gives him so much generous material, and Jeff Bridges is so unbelievably good, that instead of wanting to look past Obadiah's turn to get to the denouement, we want as much of him as possible. He's just deliciously fun on-screen and the fact that we all know the reveal before it happens hardly matters.
* Also finally, a word for Gwyneth Paltrow: She's pretty great here. It's weird to see her playing insecure, but she does it just about right and the fact that she isn't a damsel in need of saving is just one of the many, many clichés that Iron Man avoids.
The great achievement of Iron Man, to my mind, anyway, is that probably a dozen times there's a cliché looming, but the script turns away from it and makes a more interesting choice instead: Tony doesn't kiss Pepper; the government agents and soldiers are neither evil nor incompetent; the terrorist villains are not misunderstood or omnipotent; Yinsen is not killed because of Tony's actions, etc. etc.
And even better, unlike Batman Begins there are no "movie moments" where the film stops abruptly to nod to the audience by having a character say something like, "Does it come in black" or "I gotta get me one of those."
In other words, Iron Man succeeds because it takes itself seriously as a bit of film-making. Very few superhero movies--and almost no summer movies--dare to accept that challenge. Good for John Favreau, et al.
10 hours ago