I'm slighlty obsessive compuslive about things being tidy. All the tins and boxes in the pantry have to face forward with their labels and be in line with each other, I hate finding lights and other electric stuff left on for no reason, the toilet seat (the cover, not the ringy thing) has to be down (probably because I don't like the tought of anything falling into the bowl) and when I put my shoes away the shoelaces have to be inside the shoes. There are other little things like this but you get the idea.
I aslo love the sulphery smell of used fireworks for some reason (and wet earth after the rain... mmmmm).