Me thinks I have found the entry I shall vote for....
Nice work Torq, that is really cool. I like the "roof" line below the main turret, it's a rather nice effect and very realistic. Great job on the flagstones for the floor, those are sweet... did you do those by hand or use a mosaic filter in PS? And the broken stone/mortar showing the underlying base roof material is really a great artistic touch that makes the floor come alive (thought they don't look quite deep enough inset to match the tiles that are laying around thickness wise).
One thing about the background though, the scale make it seem as if the "camera" is about 10 stories up. Not a complaint, just an observation.