Zombies. Long before this whole "let's zombify everything!" trend... I don't like dead things for the fear they're not really dead. I wouldn't even let my mother bury our pets in the backyard for fear of them raising from the grave.
My fear's version of Zombies only make an appearance as the sun goes down though (kinda like from I Am Legend I guess...).
I like being scared though, so I watch a lot of zombie movies. I even have a few zombie games that I play... one of them I can only play for short bursts or I can't sleep because I'm so scared. lol.