Most things by Stephen King leave unsettling ideas in my head, but The Stand freaked me totally, because it seemed so possible- all those people trying in vain to escape that plague, images of cars full of dead people trying to escape- won't forget it in a hurry!
The other one of his that seemed to touch a spook-spot in me was Desperation- the cop who wasn't a cop featured in my nightmares for a while!
The Haunting of Toby Jugg is a leave-the-night-light on book. And if you want to lie awake all night listening to every little noise and imagining lunatics "creepy-crawlying" around your house, read Helter Skelter, the true story of Charles Manson!