Well, that would be a tough one. I would have to say Alpha Kappa Alpha, the major reason being that I heard of them first, way back in middle school, when for two years in a row, I was an AKA scholar, and I actively saw that they reached out to their community. I also have some distant cousins and aunts that are AKAs.
Just my .25, I mean .08 cents *ROTFL*
RM