I know one of the main reasons most of you visit UltraLinx is due to the awesome wallpapers I post regularly. Of course my site isn't the only place you can get wallpapers, but it can be hard finding other great quality sources.
Androidwallpape.rs is a relatively new site which has a great collection of wallpapers. More wallpapers are being added regularly and they're very good ones at that.
Even though as the name suggests, the wallpapers are your usual desktop size because Android doesn't need a specific size. It can take most desktop wallpapers and fit them really well on your device.