Definently for me it is The Exorcist. After that it is Damien. Don't know why, other movies don't scare me it is just those stupid ones with demon children killing adults...Go figure.
What its not scary its a suspenseful movie and its really scary to me it has its moments but i dont think that it is scary at all, but any ways another movie that i thought was scary-ish, was the first resident evil now that had me going.