Okay, so this may be an oldy, but it can not be beaten if you want a horror film. It is not scary like the more modern horror films, it's just very disturbing. I didn't think it was very scary, solely for the fact that the main thing that I'm scared of is there not being anything after death, and this film suggests that there is. However, I went to see it if a load of my male mates, and they all thought it was one of the scariest films that they had ever seen. One of them lives two minutes from the cinema, and refused to walk home afterwards!
So, if it's a scare you're looking for, I recommend this film whole-heartedly to you!