Since we're including food hang-ups...
I won't eat tomatoes or tomato-based products. No ketchup, no spaghetti sauce, no steak sauce with tomato paste as an ingredient, etc. If tomatoes were used in the preparation of my food, I won't eat it.
I tried to force myself to eat spaghetti sauce in college once, but after two bites I started throwing up. Ugly, ugly scene.
BTW - reading this thread makes me realize I'm not as neurotic as I thought.