Ghost Story, by Peter Straub. I've read tons of horror and suspense, but this one uses psychological terror that made me begin to doubt my own mind. The movie sucked, however.
Check out Michael Marshall - The Straw Men - serial killer mystery, terrifying, and very original slant. Last in a series of 4. Marshall is a very talented writer who deserves more attention.
The Shining by Stephen King
Then the film killed it.
Christine by Stephen King . The movie does not even come close to conveying the horror of that book .
Salem's Lot Stephen King He makes you believe in vampires. Scary stuff.
The Shining novel WAS scary - but not the movie. To me, King's scariest book was Pet Sematery {sic}.
Red Dragon by Thomas Harris - much scarier than Silence of the Lambs or Hannibal

working