I am... addicted to... buying nail polish and painting my fingernails (toenails too, but not so much in the winter- they are really bad right now, actually). Second to food, I probably spend the most money on nail polish. Okay, hopefully that's not really true, but that stuff can be expensive!
I have to specifically ask my friends to keep me away from the nail polish sections in stores if I've already bought some that week. You think I'm kidding... but I'm not. I can't keep myself away from it.