I'm not usually a fan of scary movies, but I love this film. Shyamalan's writing and directing are brilliant. There's not a lot of action, but the dialogue is deep and thought-provoking. And it has one of the most beautiful scenes I've ever witnessed on the screen (I won't give it away, but it's near the end).
Note to writers: if you want people to be scared during your movie, don't put aliens in it.
I enjoyed this movie and although it's not one of M. Night Shamalayan's best, it has what I would dare to say is one of the best suspense scenes in cinema. That's a big accomplishment. It's the scene where Joaquin Pheonix's character is watching tv in the closet. I won't ruin it for you, just watch it.