I guess we're a little past Halloween now, but anyways...
I've never been a super huge fan of horror films, but do enjoy the occassional one.
28 Days Later - Perhaps not "jump out of your seat" scary, but it was definately intense and had it's moments
Alien - Although I consider this to be more of a Sci-Fi movie, it definately has it's share of freaky and jump-out-of-your-seat moments. Still a classic.
The Ring - I'd second this movie as well. I remember it not ending when I expected it to, and that was a good thing.
Hostel - This movie freaked me out for days. It's because of this movie that I now have no intention of going anywhere near eastern Europe.
Saw series - At this point, the series has become as cheesy and campy as many other long-running horror movie series (Friday the 13th, Halloween). I find it to be good, stupid fun, but not really all that scary.
The beauty of a LEGO MOC is not the elements that go into it, but the way those elements are put together.