Here's mine:
In preparation of Fallout 4, my favorite drink from the wasteland:
So how do you manage to use them as wallpapers? Can you do it on a mac?
In X11, passing the -root commandline argument to any of the screensavers makes it draw on the root window, which is the background window wallpaper usually gets drawn on. I know that there is an xscreensaver port for OsX, but I have no idea whether -root works there. Probably not, since x11.app is rootless, but try it and see.
I need to change it now that Steve's in charge, but am using this one as a show of support for Pao / ironically because it's supposed to be an anti-Pao message.
Main reason is because of how much Reddit hated her. The amount of sexist and racist comments made about her were disgusting. Her husband was involved in some shady stuff that maybe she had ties to though. Also because supporting her made pRedditors mad.
Do u like my new background? http://www.tomswallpapers.com/31365-ubuntu-minimalism-purple-linux-background.html
http://alpha.wallhaven.cc/wallpaper/102435 a boy and girl on swings
Mine on the phone us from a lake near where I live. I will add it as soon as I am back at my lovely computer and not on my tiny phone.
I have a bunch of paintings that rotate daily. I wish I had more though, but it's not so easy to find good ones.
Any one of my 2000. Most of them are mlp-related
I've had my wallpaper cycle through the different start screens from the game Ikaruga, http://imgur.com/a/LAxmS Though right now I'm just using a simple gradient. 
See my Twitter header image, with the retro spaceship? Just like that, but 1920x1080 instead of whatever gobbledygook dimensions Twitter needs for that header nonsense.
I was about to say "aw man, I have to create an imgur account or something, ugh..." but then I realized I have a DeviantArt account I never use to upload art with...