I've always loved Iron Man. My brother used to collect the comics and when I was old enough to read, I'd sneak into the attic and read through his collection.
I don't want to give away any spoilers, so I will try and be as vague as possible, but be aware that there might be some things that are spoiler-ish.
Robert Downey Jr is the perfect Tony Stark. I don't know if there is any other actor thta can pull off the character as well as Downey did. He is the billionaire playboy, his is imperfect, he likes to drink, but he is a genius. A genius who has his world turned upside down and he has an epiphany.
Stark wants to correct the wrongs done in his, his fathers and his companies name, but he is not above revenge or killing if need be. No this is not Batman or Spiderman where they abhore the very thought of killing another. If you need killing, Iron Man has no qualms about it if you have it coming.
The supporting cast is great as well. There is some foreshadowing(war machine, s.h.i.e.l.d) which would be great for future sequels or spinoff franchises. Jeff Bridges plays Obadiah Stane well, while I'm not a Gweneth Paltrow fan, she does a good job with her role as Pepper Pots.
Overall there are a few major "iron man" scenes, the move was listed as 2:06, but it felt way shorter than that. The pacing was great and I could have watched double that and not minded one bit.
Before this, my favorite comic franchises were Raimi's Spiderman Donner's Superman, and Batman Begins. Iron Man now takes the top of that list.
On a side note. There were 2 trailers at the beginning of the showing. The Incredible Hulk(the CGI still looked like Ang lee's cheese to me) and The Dark Knight. I'd say out of those 2 Batman seems to be tops.
I thouhg the CGI was well done and played together well.