How much money are we talking about? Let´s say slightly richer than Bill Gates 
If I had like, $80 billion I would keep $20 billion for "myself" and $60 billion to everything else.
$1 billion would be for my family and friends.
$10 billion to buy as much of the Amazon as I could.
$10 billion to try to help Africa, at least to avoid people from dying from hunger.
$10 billion to cancer research, as I hate that fucking disease so much, and if I was lucky enough to find a cure, I´d make it as cheap as an aspirin. No one would die of cancer if I could avoid it.
Then for the selfish part, I´d buy whatever building I want in London and make my own museum where I would exhibit my artwork. I would buy a house in New York (I just love those lofts so much), one in Greece, one in Japan, plenty of houses in Spain and then I would buy an island, built the house of my dreams there, buy all the things I may like (electronics, computers, videogames etc.) I would fill it with cats, turtles, monkeys, birds and sloths and I would plant all the plants, trees, flowers and cactus I can. I would spend the rest of my life drawing, taking pictures, watching tv series, playing videogames, taking care of my animals and just being happy. I´d also travel all over the world with my friends and family or they could live with me in our fortress of solitude xD
With all of that done, I would still have like $20-25 billion, which is enough money to keep doing good things for what I think would be necessary. And all of that money would be on the bank, so every year I would earn more because of the interest rate.
Oh, and as for the selfish part as well, I would travel to outer space, but just when I´m old enough so if I die on the trip I wouldn´t matter hahaha.
EDIT: Oh! Forgot something important as well. I would have Zac Efron, Joe Jonas, Tyler Posey, Colton Haynes, Adam Rayner, Andrew Garfield, Ryan Gosling, Jake Gyllenhall, Ian Somerhalder and Daniel Radcliffe as my bitches. Everything on the list would be impossible, Africa, the Amazon, the Cancer research... so this doesn´t have to be any more real than that. So they would be my bitches, period!
God, we would have such a great time playing... videogames
