When choosing the image that goes on my desktop, I often choose something artsy, cute, and vaugely offensive. I'm not one for putting a big picture of my cute family up there (although I do keep those pics safely tucked away in a drawer. They somehow offer more satisfaction when they're encountered by surprise.). So the images by Kozyndan are perfect for me--and they also offer posters, coloring books and t-shirts through their website, Kozyndan.com.
Their artwork often depicts Japanese and American street scenes, animals doing strange things and extremely detailed panoramics that will give you a "where's Waldo" type experience, often throwing in walruses, record players and businessmen wearing schoolgirl outfits all in one chaotic scene. Some of these prints may come in strange sizes, so you might have to spend some dough with custom framing, but they are on the whole extremely affordable, at around $15 not including shipping.