If there was a defining characteristic between thriller and horror, then that characteristic is Rob Zombie's House of a Thousand Corpses. The only movie I've hated more than this one up to now was Movie Review - Jackass. Through the skeleton plot we discover a house full of escaped insane asylum inmates, all of whom are obsessed with death in its many forms. Some kids who are touring the country stumble upon the house and are all eventually killed in horribly disgusting ways. Thats about it as far as plot goes. The actual film consisted mainly of a horrifying series images and footage which was more than enough to turn my stomache over and over again.
I ended up watching this entire film, though in retrospect I would have stopped it at my first incling to do so... but in my niave state I decided to stick it out and see where it would lead; it lead to the most disgusting depths of gruesdom imagery imagineable.
Do not watch this film.