I really enjoyed Signs. If you've ever been near (or in) a cornfield at night, then the scene where he sees an alien leg out in the field is... incredibly creepy.

When you watch it a second (or in my case a 50th time) you start to notice other things about it. Like when he investigates the crop circles and the beam of his flashlight goes away when it hits the landed UFO, then the beam comes back as he moves it left to right.

So much good stuff in this movie and people hate on it so much because of the water ending.