You know, I sort of wish I hadn't liked Iron Man so much. Then I'd be able to say something different from what I see everywhere on the net and hear in conversation. But you see, it's all true. Everything good you've heard about this movie is 100% right on. The acting is great, the effects are well done and still special effects (not overdone), and the plot reduces the character to his most essential elements and works from there.
A big reason many of us die-hard comics fans were so (rightfully) excited is because Jon Favreau, the director is... well, one of us. He's been looking to do a Marvel movie for around ten years now if you believe the rumors, and he finally got his shot and quite a bit of budget to do it with. It's actually a joke among my friends and I that scripts for movies more in line with the Spider-Man and X-Men (read: Wolverine) films, but Favreau rejected them on the grounds that they'd have made crappy comics.
And really, that's why Iron Man rocked so hard. It really felt like a good adaptation of a comic, even without being one. And the Iron Monger suit was like watching a steel-plated Hulk; bulky yet graceful... nice.