Well this is kinda complicated for me. My Psyche is a little messed up, so I have had some really horrific nightmares that don't scare me anymore. My most general fear is a powerful enemy that I can not overcome easily. Let me explain what I mean a little better.
For instance, a cow is huge, heavy and very powerful when compared to a person. Beating one on even ground could prove to be quite hard. However if I'm armed with a firearm suddenly my fear of the Cow is a lot less than when I am unarmed. I am fully aware that Cows usually are not dangerous, and being afraid of them is rather silly, but the fact is they can seriously injure you if they happen to have a mind for it. In that logic I am utterly terrified of sharks, whom can destroy me, without me having any real chance to fight back, at the same time I love them, because they are aggressive, and bloodthirsty creatures. It's only driving force is Hunger.
This is just a general rule for me, however the other part of this is, when I am afraid, it usually triggers aggression in me. If I'm scared I will get very aggressive and violent. Games tend not to scare me. Catch me off guard? Yeah sometimes. Cheap shot me? sure. The only game that genuinely made me feel pangs of fear was Resident Evil 3 Nemesis where Nemesis would chase you down. I knew full well he was beatable, but fighting him every time he showed up would be to costly, and I would not have enough ammo to continue with the game, and on top of that he was freaking hard. So fighting him was mostly unthinkable. He was so strong, but he was just a strong enemy. So much stronger than me, and faster, that I could barely flee from him. The later parts of the game didn't do anything for me, but the earlier parts where he would chase you across the city were epic.