Another scary one is 'Fahrenheit 451' by Ray Bradbury. In this novel, books are banned and burned. The society is so controlled and people are so empty - minded. It's a terrifying vision of a future without the freedom of knowledge and thought. The way the Firemen burn books and the main character's struggle against this system is really nerve - wracking.
Well, 'The Midwich Cuckoos' by John Wyndham is also quite spooky. It's about a small English village where all the women become pregnant at the same time by some unknown alien force. The mystery surrounding the children that are born and their strange powers make this a truly scary science fiction read.