Horror Aficionados discussion

Hello! I am looking for books which are genuinely scary, eerie and can give you the creeps... Books which will suck you right in.

I recommend "The Outsider" by Stephen King and "Hannibal" by Thomas Harris. "Hannibal" is the fourth book in the series though, so for the full experience I'd recommend the whole series, but the final book was, in my opinion, the most unsettling. "Rosemary's Baby" by Ira Levin made me very uncomfortable, the same goes for "The Exorcist" by William Peter Blatty, but neither of them are favourites of mine such as the first two are.

What is genuinely scary varies widely from person to person.
Here are some books that scared me: