There's that innate fear of the slightly abnormal I found interesting. That creepy vibe you can get seeing a robot talk is linked to it. That is probably learned in human history having an experience with dead human(s) and obtained ancestrally.
I've also read it could be linked to previous links to the modern human just different enough to incite fear during times when those types were warring (ex. Neanderthals) and we kept it over time.
Personally, I'm really afraid of heights. Loud noises are a concern, but the feeling I get from heights is otherworldly and I find it intriguing simply because it is so completely different from everything else. It is definitely the instance I can describe with the word "fear".