I love Simple Desktops. You can guess what sort of web site it is.
Just simple desktop backgrounds. All of them are fantastic, and all of them look great on your Mac.
They’ve been collated by Tom Watson, who says the designs he features are for people who “want less, but not boring”. You can submit your own designs if you like.
And if these are too minimal for your taste, you might prefer to go hunting around the Command Shift 3 Flickr group where you’ll be sure to find plenty of inspiration and links to more frenzied desktop backgrouds. Personally, though, I’m sticking to the beautiful minimalism of Simple Desktops.