Forget the boogey man....
The only other time I can really remember getting scared was when we were watching the movie IT with surround sound. The movie was stupid, but when one of the characters was looking through the photo album and his dead brother winked at him, I about died right there.
It was the visual along with the loud sound effect that just came out of nowhere. It probably wouldn't have had the same effect if the sound wasn't surround sound.
I must admit, though, the short movie clip from The Ring gave me the creeps, but in a different way.