The cheaply-made Mark 1 version is the standard one-disc DVD, which merely comes with deleted and extended scenes -- the DVD equivalent of a flamethrower. The flight-enhanced Mark 2 is a two-disc "Ultimate Edition," which I presume has nothing to do with Marvel's "Ultimate Universe." The two-disc set includes the deleted and extended scenes, a seven-part making-of documentary, a six-part feature on the origins of Iron Man, a documentary on the film's visual effects, concept art, behind-the-scenes images and Robert Downey Jr.'s original screen test, which should be magically splendiferous.

The Mark 3 is basically the Mark 2 with a paint job -- in this case, the color is Blu. The two-disc Blu-ray Ultimate Edition includes everything that the regular Ultimate Edition has, plus a "Hall of Armor" feature that lets you check out the three Iron Man armors (plus Iron Monger) in detail, with the ability to zoom in and call up 3-D schematics. Man, wouldn't the Spymaster like to get his hands on that? Looks like Blu-ray is about to trigger another Armor War! ...Yeah, that was an Iron Man comic reference. Deal with it.