I prefer psychological thrillers or horror, though it depends. It often nice to have the tension build and build with some unseen threat going around and doing nasty, scary things, but sometimes its nice to get to know the beasty early on, maybe like a zombie flick, as the visual imagery is an important part of it.
Sign's had its moments, but the aliens were a bit disappointing. Locked in a cupboard? Tch, tch.