Tom Cruise — ‘Iron Man’

Robert Downey Jr. brings a little snark, charm, and edge to the character of Tony Stark/Iron Man -- perfect for a character who likes his drinks stiff and thinks he's smarter than everyone in the room. But what if Tom Cruise played Iron Man? We can totally see it.

Cruise and Downey Jr. both have the ability to play sarcastic know-it-alls with a dark side, and Cruise knows how to have a good time with an action film. Of all the almosts on this list, Tom Cruise as Iron Man is one of the more reasonable ones, we think. Cruise was set to produce and star in the film through most of the 90s and early 2000s, but time took its toll and by the time they finally had a script, Cruise didn't think it was strong enough. In a fun twist, Cruise went on to star with Robert Downey Jr. in 'Tropic Thunder,' which was released the same summer as 'Iron Man.'