I always press the outer sides of my wrists against my hips to crack them, its sort of weird.
If I'm nervous I always pop my dodgy left shoulder out and back in, its disgusting so I cover it with my hand. I never realise I do it til afterwards.
I always stroke the short side of my hair. Its awesome.
I always have to turn my radio up in even numbers, nearly crashed once trying to get from 15 to 14

.
In work I don't trust the cleanliness of the glasses in work, so I wash the pint glass that I use everytime exactly 3 times. No more. No less.
I ALWAYS fidget, I can't sit at peace.
I also always twitch my legs.
When I'm swimming I have to swim in sets of 4 x 25m, or 10 x 25m. No inbetweens. My last set is always 4 because there's 64 lenths to a mile, so it used to kill me not finishing my 10. So I swim in 4's alot now.
If stuff is lying on a table all messy, I'll leave it messy but square everything up to the edges.
No matter what the car, I take it on in my 1.3 fiesta. Not racing, I just like to be the first to pull away from say traffic lights

. If I don't I feel quite inferior/deflated/empty. Weird.
When I'm eating my dinner i never sit on the couch. It's always the poofy or the floor.
I have tons more silly little quirks. But... I can't be arsed thinking what they are.