Just a plug.
http://www.forsakenreality.com/ I found this site when I was in college. Ten bucks for a one-year subscription and I could browse and download his library of wallpapers. Because I am a sucker for good 3D art I thought, why not? Now he offer a "life-time" subscription. $35 dollars and your subscription never expires. Seemed like a pretty good deal to me.
He updates regularly. He's got wallpapers going all the way back to 2005 and in all sorts of resolutions.
I've got over a hundred wallpapers downloaded onto my computer. And since my desktop cycles on start up, I get to enjoy every one of them. If you like Digital Blasphemy, you'll like this guy.