I've always loved Fujiwara Kauro's artwork, especially when it's colored. Here's a wallpaper I've made from one of her works, but as far as I know, it isn't connected to any manga.
To view the wallpapers in full size, click on the images.
All credit goes to Fujiwara Kaoru. Please do not use these wallpapers in any public relations without giving credit to her (and if you're real' nice, you'll link to this blog too, right).