Oh yeah, Cabin in the Woods is fairly good. Drag me to Hell is very divisive but probably worth a shot.

Also yeah, I left them out because I wouldn't particularly class them as horror movies, but the Evil Dead series is mandatory watching for all human beings.

e; Oh also one of my all-time favorites in the genre looks like a typical "dumb teens get murdered" flick, but is actually superb: Jeepers Creepers. The sequel isn't as strong but probably still worth it if you like the original.