No doubt a movie about an invincible flying suit of armor would contain a lot of CG effects, but perhaps not as many as you think.  Iron Man 2 contains numerous FX shots, but some of the armor Tony Stark wears is physically fabricated with the assistance of an Objet printer.

For the sequel, Legacy Effects scanned actor Robert Downey Jr.’s hands to create flexible gauntlets no thicker than a dime, which stand in marked contrast to the gloves in the original Iron Man, which were clunky and difficult to maneuver. “He was thrilled with the change and happy to work in them for hours,” notes Objet in a press release.

via The Secret to High-Tech Armor in “Iron Man 2” 3D Printing on Demand Ecouterre.