The human body and surgery. Seriously, I can't for the life of me watch anything with real life surgery in it or cut open bodies. In other words, practically anything related to inside the human body. I have to look away.
Moles freak me out, too. I'm always overly concerned about my own.
I work in a lab, and anyone who works in healthcare will be able to tell you that the human body really is quite disgusting. Being freaked out about it is perfectly normal - the only reason more people aren't is that they have no idea what goes on in there.