What is the scariest anime MOVIE?

i would like to see an anime MOVIE that isn't necissarily the scariest just something horrific and memorible with well diveloped story and something shocking, nothing based off of a tv show. but a good anime well developed charactors back story etc. i know Grave of the fire flies is the saddest anime movie (well deserved title :{ ) anyway but any ideas i've seen perfect blue or whatever it is but give me some ideas if you can ya know thanks for your answers