1) I can't believe you haven't said anything about SLEEPAWAY CAMP, specifically the freaky ending. I saw this as an adolescent at a slumber party in the 80's and we had lots of fun mocking the lame kills and acting, but that image of Angela standing naked over her boyfriend's severed head and doing that weird gutteral "hissing" still affects me as a 32 year-old. I don't believe I slept a full night in my own bed for at least 2 weeks after seeing that!
2) A made-for-T.V. movie I saw in the 8th grade called FROM THE DEAD OF NIGHT starring LINDSAY WAGNER and BRUCE BOXLEITNER (I had to visit imdb.com to look up the name of the movie) really freaked me out. LINDSAY plays a woman who has a near-death experience and sees these weird shadowy figures in a tunnel before she's resucitated. Well, the shadowy figures want her back and begin stalking her. I don't remember much else about it, but the thing that really sticks in my memory is a kid on a skateboard who is killed and possessed by one of the spirits and rolls after LINDSAY's character in the dark (I think it was a parking garage, but maybe a dark alley, can't remember.)
3) Another made-for-TV movie that got to me was THE STRANGER WITHIN starring RICKY SCHROEDER and KATE JACKSON. I had a HUGE crush on RICKY from watching SILVER SPOONS as a kid and seeing him play such a convincing psycho really tainted my pristine memories!