For me, I hated whenever any monster attacked out of nowhere (i.e. Mr. X busting through the wall, Cerberus jumping through windows, etc). I also hated the room in RE5 when walking past the Lickers because of the suspense (I knew they were going to jump out at some point, but wasn't sure when). I also hated when the Bandersnatches would climb up a floor if you were above it because I was like, "Crap! How am I supposed to get past something that can get to where I'm at from any place it's at?!?!". It also was really shocking at the end of the first scenario in RE: Outbreak File #1 when you had to find the bomb part in that herd of zombies. Although it wasn't necessarily scary, it worried me because I had never been near so many zombies.