Lord Loss of the Demontana series. Its not that bad as a whole but the part where he comes home and meets one of the demons inside his sisters corpse is quite memorable. If we count manga it would probably be Bio-meat: Nectar. Has the feel of zombie outbreaks in the hopeless feel of the struggle to survive.
The Unwanted (100% true story) is an extremely sad and at times shocking book. Molestation, child abuse, animal abuse...I really didn't want to read it but it was for a class.
"Science and sanity" by Alfred Korzybski. It's a book on general semantics, it makes you doubt your sanity.
No one's mentioned, "Misery" yet. :C Misery is pretty disturbing, but I love it! Apparently women tend to have that as their favorite Stephen King novel. I wonder whyyy. I tend to stay away from the thriller genre, preferring to stick with more romantic, classical, or depressing things, but there is a book called, Frozen. It's about the cryogenic organisation, and a guy gets hired by them and he sees just how fucking INCOMPETENT and MESSED UP those people were. You get to see Babe Ruth's, decapitated frozen head, and its just... ugh. Frozen: My Journey into the World of Cryonics, Deception, and Death: Larry Johnson, Scott Baldyga: Amazon.com: Books
When I was younger I had these, google image the name of these books and check out the pictures that are in them, terrifying!
Believe it or not, Wolfen. The book. Not the movie. The movie was a complete disaster and didn't even come close to conveying the same tension and fright. I actually had to set it down and stop reading a couple of times. It reminded me of the Skinwalker stories I hear around this area.
Blindness Requiem For A Dream The Girl Next Door Naked Lunch Flowers In The Attic Some passages from the Bible are quite disturbing as well, the same goes for the Koran.
The scary stories series from the 90s by Alvin Schwartz and Stephen Gammel......the stuff of nightmares...
House of Leaves is seriously the most disturbing and passionate and amazing book. It made me lose my mind a little bit.
Probably gonna sound soft to those into 'horrifying/disturbing' books, but I found The Exorcist to be a bit disturbing.
Cant really say any books has terrified me, like nightmares & shit. But some that freaked me out/unsettled me are: obligatory 1984 mention, as well as Farenheit 451. The conversation Montag and his Captain have in the bedroom is some scary shit. Also the Gulag Archipelago, which is long as fuck but a worthy read. The Descent was kinda scary too lol....I really don't read very many 'scary' books though
"The Throne of Bones" by Brian McNaughton. It's basically Lovecraftian horror with some deviant sexuality thrown in. And speaking of Lovecraft, I read "The Whisperer in Darkness" when I was like eight, and the ending really got to me. But a couple of people on this thread have mentioned Lovecraft for a reason.
You might want to check out the film based on "The Whisperer In Darkness" http://www.youtube.com/watch?v=A_ee9K9hXtw&list=UUJIfN8XqPyhPo9jaSMaX-9w&index=7 Definitely one of his top stories