Yes WD when you want to watch something that shows you
how truly terrible people can be, find "Salo: The 120 Days Of Sodom".
It won't be in the horror section normally, it will be in the Foreign film
section of a good hole in the wall type of video store.
The ending is pretty intense, as is the "banquet", but also the dialogue
is perhaps the most disturbing thing about the film,
and the stories told by the lady storyteller chick are very sick.
Evidently the guy who made the film ( it came out in 1973 I think )
was brutally murdered in Italy, some say for making this film,
some say for making controversial movies in general,
and some say it was just that someone hated him. I don't know
for fact which is true. But anyway check it out sometime...
My favorite line in the movie:
"Any religious act will be punishable by the loss of a limb."