A rework of the 3DS Max model [link]
I created from a tank design by Feng Zhu. [link]
I decided it was too narrow in width and lacked enough weaponry, so I widened it and added a Vulcan cannon to the roof, plus a ton more detail.
Many people (myself included) liked the original sketch quality of the Zhu artwork, so I used a cell shader plug-in and lots of photoshopping to create a similar look.
For higher res desktops, use this image "centered" and set you Desktop color to RGB 214,214,214. Looks great with the ChosenOS skins of recent release.