For me, I think it's love. I just feel happy when i'm embraced with the feeling of love coming from another person, and it leaves me feeling like i'm not worthless. When your heart is warm, you just feel like your actions are meaningful and you end up caring for others.
Love. I believe love overcomes all. I am aware that anger and fear are very powerful emotions as well, but they aren't exactly emotions that one would like to be under all the time. Love, on the other hand, is an emotion that allows us to do things we never thought we could. Love solves conflicts, anger and fear do not. Anger and fear are destructive while love builds. That much is certain.