Quite honestly, if I was handed that much cash, I would 100% go the Paul Newman route. Food for children, free education, free healthcare... damn dude, if I were elected President, I would be assassinated the same day. I would tax anyone with a billion dollar net worth 95%.
And I would also close down the military budget. Vote for me to be dictator, and I will start practicing Neo's moves. I would be literally dodging bullets and would have to wear an anti-bear bullet proof suit.
But I would do it in a heartbeat for humanity. So much of this suffering is so easy to stop that it makes me sick.