Even if you're set in your polish ways — an Essie Ballet Slippers devotee or an unabashed loyalist to the glossy bright red by OPI — you have to be at least a little curious about what polish everyone else is wearing. We were, and so we asked our favorite nail brands which polish shades are the best sellers. You know, the colors people buy in bulk and hoard in their bathroom cabinets. The answers were not at all what we expected.