wow .....you said Phantasm..... the ending was scary!!!!
The excorcist- I slept with a cross under my pillow for a long time after I watched that movie.... I will not watch this movie to this day.
I also remember my brother said his wife passed out when they went to see this in the theater, she does not watch any horror movies to this day.
Id add:
Poltergeist
final destination movies. just the concept/plot is creepy.
Omen - the original
Salems Lot - the original.