Meh ...
I don't think many movies really are "scary" any more. Sure some of them have a bit of a shock value, and others a creepy value. But most "horror" movies are funny much more so than "scary." That said, it seems like there are quite a few that are truly disturbing.
I think purbeast0's post about being stuck in a "Battle Royale" would be amongst the most horrible.
I think "Gozu" would be a terrible movie to live through (like a never ending nitemare that you can't wake up from) and also "Audition" would be pretty fvcked up and creepy. In Audition I would simply not do the whole "audition" thing, but then of course it wouldn't be like the movie at all. I suppose I would just take the other guy's advice, and that too would probably save teh character's ass.
As far as scary goes, I guess I'll bite and say "The Shining."
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
All Work and No Play makes Jack a Dull Boy
I don't know what I would do if I was in the movie, but Jack Torrence is a fvcking lunatic and The Shining is one of few movies that still sends shivers up me spine. RED RUM!!! RED RUM!!!!!