A White Court family that fed on gluttony would be very effective I'd think. Most people enjoy eating, and it's built into our DNA to want to eat so the combination of pleasure, and an evolutionary need would make a powerful combination. I could see the family owning a restaurant empire. Many of them would just be there feeding while dozens of people are spending huge amounts of money ordering more, and more food.
Some of them would be pretty bad though. They would keep people locked in cages, not allowed to eat, and then when the vamp wanted to eat, they would bring huge amounts of food for their victims. the people would be stuffing their faces, and so would the vamp in it's own way.
They would be huge vamps too. There superhuman speed, and strength would still be there though.
