I think you can handle Paranormal Activity although be prepared for higher electric bills. I had to leave the light on in the living room every night for at least a week after watching it.

The Evil Dead is NOT scary while you're watching it. Every one of the seven times we watched it we sat there and made fun of it. It only becomes scary later, when the woods are so dark...and the house is so quiet...and suddenly you hear something rustle by outside, under the window...

I am, of course, watching The Walking Dead. It is terrifying AND grotesque as it bloody well should be.