5. War Machine/Iron Patriot
Col. James Rhodes (played by Don Cheadle) dons a suit of his own and becomes War Machine in Iron Man 2. He helps Tony save the world, and then gets a bit of an upgrade in Iron Man 3, complete with a paint job and name change, as he becomes Iron Patriot. Rhodes didn't have a lot of screentime (in the suit, at least) in IM3, and was completely absent during the events of the Avengers. He's a cool character, the fans seem to like him, and Cheadle has expressed an interest in reprising his role in the future. Why not give Col. Rhodes a mission of his own and make him the focus of a One Shot? After the events of IM3, it's unclear how Tony Stark's role as the armored Avenger will move forward, but there's nothing to indicate that Rhodes retires as Iron Patriot. It would be interesting to see what he was up to between the events of IM2, The Avengers, and IM3, and a One Shot could be the perfect opportunity for Marvel to capitalize on our curiosity.