The original Amityville Horror from 1979 is regarded by some as a classic, but in most ways, the 2005 remake starring Ryan Reynolds is superior. Based on the allegedly true story of the Lutz family, The Amityville Horror was first a book by author Jay Anson, which was then adapted into a movie.
1. The Amityville Horror (1979) This was obviously going to be number one. Despite not feeling terribly spooky to me anymore, it's definitely the scariest of all of them; anyone who watched it as a kid had nightmares afterward.