I didn't like either SAW, they were both kinda, meh.
Hostel was boring and made me regret buying the large tub of popcorn.
As far as I'm conserned with horror films, they have to actually:
a) make me jump
b) once the movie is over remain in my head with a 'what if...'
it's why the alien movies are the only ones that truely s**t me up, and that's why i feel they're possibly the best horror series of all time. (especially Aliens)
Terminator and Robocop, the first movies were very good horrors. I mean Terminator after you watch it alot looses that scareiness; but for some reason the sick nature of that gang in Robocop doesn't.. maybe cause I know full well there are gangs like that in the world.
Predator was another good one, it kept you on the edge of your seat because you didn't know what was going on.. I guess it's the same reason I liked Pitch Black. I've not liked modern horrors because they've just been trying to gross out the audience and take the fear factor from real things. Problem is with real things is it's not *as* scarey because at the end of the day, your not using your own imagination at all. I've always found that's what scares me the most.