In this order:
1 - Tickling. My wife used to love tickling me when we were dating and she never understood why I would suddenly withdraw and get angry when she did it. In fact, at the time I didn't understand it either. All I know is, tickling has always been painful to me and I absolutely cannot stand the feeling.
2 - Dryness. When my hands are dry, it bothers me a lot. I keep a bottle of lotion nearby, but I am very specific about that kind of lotion I like. I normally have to try a few different brands before I find one that feels right on my skin.
3 - While I do not like dryness in general, when it comes to toilet paper and Kleenex, I cannot stand the ones that have moisturizers built into them. That oily feeling on my skin is similar to what I dislike about many different lotions and I cannot stand it. I also am extremely particular about the type of toilet paper I will use. It has to feel just right or I cannot use it unless I am in a major bind.
4 - Sudden and/or loud noises. Doorbells, motorcycles, loud car engines, smoke detectors, alarm clocks, telephone ringers, airplanes etc all spook me. I grew up next to an Air Force base and the huge planes flew really low over my house all the time. I never did get used to that. If I was outside, it was the worst and I would cover my ears and scream at the top of my lungs.
5 - Extreme sunlight. When I was a teenager I loved the summertime and swimming, but I never have really been a fan of the sun. I have noticed all my life that even when people around me are not squinting, I usually am.
Add any of my most hated sensations together and you have a recipe for disaster. Too many people talking at once, or voices on top of music, on top of bright lights, on top of dry skin, and I will go off on you in a split second with absolutely no warning.
Also what sets me off is if I am in the middle of something and someone begins talking to me. I cannot multitask, so my head begins to hurt really badly and I just snap.