I was anxiously anticipating this film ever since the first trailer was posted online. The biggest challenge with these comic book-based films is satisfying both the devoted fans of the comics and those who've never cracked open a comic book in their lives. I can honestly say that this film meets and exceeds that requirement.
Robert Downey, Jr. was perfectly cast as Tony Stark because both characters are brilliant men who've struggled with substance abuse. He kept me rolling in my seat with laughter, and when I wasn't laughing I was engrossed in the action sequences, superbly enhanced by George Lucas' special effects company, Industrial Lights & Magic.
I'd recommend this film to all. Oh, and make sure that you wait through the credits for the short clip that plays afterward. I smell a sequel!