I have a bunch I found that I think are cool, but here's my main pick
Old_Timey.wsz
An interesting bit behind what I was looking for here: I always thought the interface for the Sega game "Soldier of Fortune" looked pretty cool (the game's got a mystic vibe about it mixed with mercenaries and military dudes, including a scientist with questionable character; not that that's a bad thing), so I went to find something that had a more military style, and there were a bunch that looked good (and they did have the Soldier of Fortune skin as well). I picked the one that I wanted that closest matched Ross's criteria from the GUI video. This is a darker theme (that part is kind of my preference) - but not too dark in case you go to look at a bright picture or something, since it has those lustery spots and plenty of room to add lighter shades. I have a runner-up theme that might match that criteria better, but I didn't know how dark Ross would allow, however I still picked this one for the contest because it matches Ross's computer theme where he's got his surface and core drives, and this sparked my imagination of taking a submarine to the bottom of the ocean to take a gate into the core of the planet. Or even a similar machine to withstand pressure drilling into the surface of the planet.
I LOVE IRON HARVEST!! SAXONY FTW!
Favorite line from the game: "What does the empire require?" Gives me goosebumps knowing the Third Reich is coming.