After seeing "Sixth Sense", I would close my eyes, plug my ears with my fingers and hum (I probably looked like an idiot in the theatre doing this) at the trailers for his next movies, not wanting ANYTHING spoiled.
"Unbreakable" was completely blind and I LOVED it. I had no clue it was a superhero movie (not sure if any trailer alluded to that, but I'm glad I didn't take the chance)
Same with "Signs", water weakness and all.
"The Village" was blind, too, but maybe I should have watched the trailer so I would have known to avoid it...
(There were some good moments, and it had GREAT atmosphere, but overall was pretty bland)