The first person I thought of upon reading this question is my boyfriend. He doesn't smile all that much, but it makes me feel good when he does. Sometimes he smiles because he is laughing, and other times he smiles on one side, in a charming, romantic way. I like that one during romantic moments. Then there are the smiles when he hears something, like good news or something cute about our unborn baby kicking, and he looks truly happy.