"It" scared me up until I was about 10. Other movies that scared me before that were Candyman and Children of the Corn.
My cousin(Iwho was my age) used to love children of the corn so we would watch it everyday.
Candyman I saw alone in the middle of the night. Can't remember which one it was, but I remember the teacher(?) had to break a mirror or soemthing.
I still get nervous when I watch "It"