Well, we're all packing up for a move here in my house so I thought I'd post a shot of my small collection of Unicron figures I have before they get boxed up.
I of course have the original Armada figure but to the right I have the 25th Anniversary retool version with the new head. This uses the same mold as the Japanese version, but I really rather prefer the US release seen here with the darker metallic oranges, metallic grays and darker slate gray than the Japanese colors.

Down below are two smaller versions of Unicron as a sort of battle ship, and in the center there's a Transformers Prime version from Japan standing above a severed and somewhat wrecked head of Unicron from the figure of Primus released in the Cybertron line.