The Mark 1 is great, and it's especially great because it's armour over an actual figure, but, for me, it's the Mark 2, which is equal with the Mark3 and Silly Thing version, but with the rivets it is just that bit more unique and it looks better, that takes the prize so far this year for best figure.
The engineering of the figure, it's parts, it's articulation, the numerous compartments, the lights, the magnetic face plate. The added head and light up reactor accessory push it over the top. Make mine a Mark 2.