A site I am drawn to for all the wrong reasons is Albino Blacksheep. They seem to specialise in Flash animation and if you follow the links you need the sound on. The first is one boynton sent to me some years ago. Seems harmless enough...
This next one has certain crass appeal but one of my particular favourites is Pie Hole. Browsing around Albino Blacksheep you'll find some bizarre animations not to mention the 30 second Titanic, The Shining and The Exorcist - starring bunnies. Most diverting - particularly if you've got broadband connection. I wish!