To me the scariest movie is "paranormal phenomenon",bacause i have not seen before such kind of movies.Usually use the same plot ,for example a young couple with some children .And every night start to happen strange events as rustling in their basement ,missing things ,white traces on their floor ,above all ,it notice their children .Someone of their children see the old hosts `ghosts and force them do something what they do not want.The end of movie was very unexpected to me .During the movie was a tense situation .
There was a time in my life I've been watching scary movies like crazy and THAT movie Haru just mentioned has always been on top of my list of "the most scary movies of all time."
if you are looking for a memorable scary movie. Check it out. (But I wonder if people from non-asian culture would also think of the movie as scary...)
The most scariest movie that I have seen is Ringu (リング Japnese movie). It was quite popular when I sudied at middle school. I borrowed the dvd from my classmate. Just out of the curiosity, I watched it. The scariest moment in the movie that I can still recall is that the ghost crawled out from the TV. Hehe. You can't imagine how scared I was when I watched it alone at night. For the next whole week, I was too scared to go to home and open the door alone. I was worried something unusual would popped up in front of me suddenly when I opened the door. So during that time I would usually wait for my parents near the lamp post. Hehe.
Here is the link of the introduction of the movie if you are interested. Hehe.