David Green, founder and CEO of Hobby Lobby

Net worth: $4.5 billion

While he could easily afford a Gulfstream of his own, Green, founder of arts and crafts retail chain Hobby Lobby, prefers to fly coach.

Instead of spending his billions on himself and his family, Green has famously become the largest individual donor to evangelical causes in America. He's given upwards of $500 million in charitable contributions over his lifetime, according to Forbes.