Hearing and touch. I hear everything. In every place I've lived, I've been able to hear people talking from any room in the house/apartment. I sleep with earplugs, but it doesn't block enough. So I still hear things going on outside my room. Plus, then I hear the blood pumping through my veins, and then hearing it makes me feel it, and it's really bothersome and keeps me awake.
Touch I notice every object my body is in contact with at any given time, and feel the movement of nearly every hair on my body. So when I try to sleep, I'm far too aware to how the blanket is sitting on me. And if the air conditioning or something is blowing, it will move some of the hairs on my arms and legs and make it feel like there are bugs crawling on me.
I also can't sleep very well with a lot of light in the room. Or changes in light. Any charger or display that has a pulsating or blinking light needs to be covered before I sleep.
As you can guess, I don't sleep very well. I don't even know if it's my senses being that good so much as I am hyper aware of what it going on around me at all times. In any given room I'll be aware of everything. Light sources, exits, ceiling height, distances from each piece of furniture, most efficient path to xyz, etc. If it's somewhere I live, or have been frequently, I'll typically be aware of all the creaky spots on the floor and other areas I don't like stepping on for whatever reason. I wake up for sound differences as slight as my computer's fan lowering its speed, so I usually wake up at least 5 or 6 times a night.
I really wish I could turn it off sometimes. At least so I wouldn't be perpetually exhausted. When I have the money I want to buy a coffin or something and sleep in that.