The 1963 film The Haunting (not the one from 1999). It's black and white, you don't see virtually anything scary, basically just noises. But nonetheless the scariest film I've seen.
I find films like Blair Witch, Paranormal Activities, The Haunting so much more scary because you see very little, it's not in your face. It's about suggestion, building the atmosphere and the tension etc.
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Now: Ford Fiesta mk6.5 ST150 2.0 16v
Then: Opel Tigra A 1.8 16v 160PS; Ford Fiesta mk3 1.1i