The Haunting of Hill House by Shirley Jackson
This classic horror novel is the basis for a couple of horror films called The Haunting, including the classic 1963 version and the almost universally despised remake from 1999. It follows paranormal investigators who spend a few nights in a haunted house where things take a rather unfortunate turn.
Scare Factor: 4 - Definitely creepier on the page than it is on the screen. Not for horror novices!