As Much as I love Argento (Well at least argento until the 90’s! 
) I’ve never really found his stuff all that scary. I’m usually geeking out over a shot or the lighting or just enjoying the whole detective story of the thing.
The only film that scared me recently was The Exorcist (The original), a lot of people don’t think so but theres something about the atmosphere of that movie thats got a real malevolence behind it.
I actually havent seen Drag Me to hell yet but my friends said they were actually scared in the cinema watching that.
