Really late but I figured I'd chime in on this one.

Blindness and complete deafness are tied for first, with deafness actually pulling ahead. Blindness would be terrifying at first, but I know I could learn to live with it. The reason deafness is a bit more terrifying is because quite frankly, I rely more on my ears than my eyes.

Total silence is also scary as hell. The few times in my life I've experienced it I couldn't deal with it, I had to make some kind of noise to deal with it.

Third on the list is needles. Just typing this is making me shaky. True, one of my ex's is a diabetic and that helped a bit but still, I can't be around them without freaking out.

On the plus side, I'll never get into heroin...