Salad Fingers/Nightmare Fuel


 * The fact that most of the music is done by Aphex Twin (of "Rubber Johnny" fame; see here for more on that) and fits the tone perfectly should be your first clue that you're in for a freakfest.
 * David Firth, creator of Salad Fingers, also did a claymation video with the subject "Hell". It starts of as a fascinating use of stopmotion/claymation, but as the video goes on... well... claymation has never been so disturbing. The second time I viewed it -with the sound turned up a bit more- I had to switch it off after a while: some things are not meant to be heard. I remember that the video was quite hard to find back in the day on Firth's site, and there were plenty of disclaimers before starting the video. David Firth is decidedly not a liar when he goes as far as to put a disclaimer on his work.