The reason I liked Blair Witch was because it left a lot to the imagination. Not many things do that anymore. You know the old saying, 'sometimes it's scarier if you don't see it'. There is nothing more vivid than the imagination. If you take it at face value, theres not much too it. I have an over active imagination. Sometimes thats not a good thing.
Anyway, a movie that has not been mentioned yet, that is one of my all time favorites, Kubrick's The Shining.