[ams]

These are the primary focus of my current collection--here's what I believe is a fairly exhaustive list.

Mark I
Mark I (v2)
Mark II
Mark II (armor unleashed)
Mark III
Mark III (battle damage)
Mark III (gunmetal grey)
Mark IV
Mark IV (secret project)
Mark IV (w/ gantry)
Mark V
Mark VI
Mark VII [March/April 2013]
War Machine
War Machine (special version)
Iron Monger

The only ones I don't have are the non-armor figures (stark, widow, whiplash), the gantry, and the yet-to-be-released Mark VII. There may have also been another re-release of the Mark IV in there somewhere.

The only guidance I can offer around collecting these is to lock in your preorder as early as possible with your favorite vendor.