Lighting. Nothing ticks me off more than someone coming into the room where you are, turning on a bunch more lights just to say something to you and then leaving. They seem to think that there 'needs' to be more light in here, or that you should have more lights on. Let me go turn off all the lights where they are when they are in the middle of something. They'd flip.
I can't stand bright sunshine or outside daylight in general. I usually drive with my visor down during the day, even if it's cloudy. My eyes always look like I am stoned or tired. No one understands that light is physically painful for me.
Sounds. When I am listening to music I like, I can handle the volume cranked up to 11. At the same time, the smallest noises can sometimes irk me to no end. Noises from TVs, monitors, lights, crickets outside are the worst I can think of right now.