Everyone has a different taste when it comes to their desktop.  Some like extravagant setups and some like a very minimal look.  For me personally, I like desktops and skins with a nature based theme.  Maybe it's because I spent most of my time indoors, but who knows.  I have taken notice of a member here at WinCustomize who does some outstanding photography, and uploads some of it in the form of logons for Vista.

That would be OutdoorPictures. John also has a great collection on photographs on his Flickr page, and many of them would make great wallpapers as well.  If you have LogonStudio Vista, head over to his WinCustomize gallery and grab some of the those logons.  I hope one day he expands his work to other galleries.