InterfaceLIFT - High-resolution widescreen wallpapers, desktop icons, and themes for Mac OS X, Microsoft Windows...
Wallhaven - Your source for the best high quality wallpapers on the Net!
Desktop Nexus - Download free computer wallpapers, pictures, and desktop backgrounds.
HDWallpaperGreat.com - HDWallpaperGreat.
Ultra HD Wallpapers - One site with wallpapers at high resolutions (UHD 5K, ultra HD 4K 3840x2160, full HD 1920x1080) for phones and desktop. Download 4k backgrounds to bring personality in your devices.
Digital Blasphemy - Hi-res original 3d-rendered computer desktop wallpapers.