Here is my humble nomination.
Discuss, or share yours?
(Please note I don’t mean “worst” to mean “most horrible” or “most gory”, just the direct opposite of “best”.)
Wow, that’s poorly done, poorly planned, and based on a piss-poor concept.
At that angle, I think the hammer is gonna miss the nail altogether.
Gaah!
twitch twitch
That image offends me. Lame, overused simile (or metaphor or whatever it is), plus crappy drawing and crappier colouring. I can do better with my left hand tied behind my back.
When I was in electronics school, I has a teacher who used to draw rally bad drawings of things on the board. That was okay, though; not all of us are artists. What made me grit my teeth is that he always said, “As you know, I am not an artist,” before drawing it. He became known (and mocked) for the line.
This drawing is worse than that.
Oh, I’ve got a few candidates as someone that has to make these crappy things behave nicely in my app.
One more bathed in excellence. (Note: same source as above)
I’m sorry for inflicting it on the world, but it just cracks me up like nothing else. I don’t know why. The horrible colors? The “almost but not quite” realism? The aim of the hammer? The BOLD TEXT?
Here are some other winners/losers:
Fruit basket
Classy cropping job
Just die already
Damn, Dooku. Those dinosaurs now have a home as my wallpaper.
I may say NSFW, but it really defies any category. I would go so far as to say NSFH, either. No, nothing disgusting, just some artist with some issues, and a basic misunderstanding of biology. BUT, if you were ever curious how seahorses are made…
http ://www.cetacean-creations.com/xphins/horsefem.jpg
It was covered under an past thread, where posters’ commentary had me in tears.
The “fruit” picture contains a visual double-entendre. Not sure if that is the main
reason you chose it or not…
For some reason this reminds me of that ‘warning sign’ where the stick figure talks about what’s going on with him in signs depicting things like ‘do not stick your arm in the woodchipper’ and ‘beware, hazardous materials’. Does anybody know where that is?
I made Dooku’s cats my background. This should be a grea thread for awful wallpapers.
’druid, where the hell do you find these images?!
Yeesh! That’s *incredibly *awful. My vote’s for this one so far.
Imagine me getting these images in bug reports b/c they were causing problems in my app and having to examine them closely while bug fixing graphics code. You’ve never seen such procrastinating. “Sigh. Nothing left to do. Should I look at that fucking Cat Cloud picture or Dinosaur Campfire some more?” ::immolates::
“Step 1, put your junk in the bowl”
“Whoa. That’s some really good fucking catnip.”
My new background!
It’ll make the wife jump when she sees it. 
“Step 2, cut a hole in the bowl”
Oh boy. I have some more submissions.
This one isn’t too bad, until you read the haiku that accompanied it:
grinning at the wind
old woman sits in pee…
her own warm pool
Also for your consideration:
Bad Habit (A little NSFW)
Okay, I feel kind of bad about this once since it’s made by a kid, but still:
Rainbow Roar
Google Image search plus lots and lots of wasted time. Still, I like the Dinosaur Campfire the best so far.
I think I just threw up in my mouth a little.