I know these pail in comparison to movies you guys have listed but:
The Accused, the rape scene may not be the worst ever on film, but damn it really bothered me for some reason...
Candyman, sure I can watch it anyday of the week now, but when it first came out, it spooked the hell outta me, i had to turn the lights on in the bathroom before I went in...
Arachnophobia, I'm very arachnophobic so this one really set me on edge...hell I thought I could feel spiders on me while watching it at the theaters!