Answering fully would reveal a little more than I care to about how much time I had spent thinking of this. ;-) I think you'd have to give some serious thought to not having sudden wealth ruin your life and that of those you love most.
But at least: I would build a nice studio with some skylights and a high ceiling.
Ben,
Recently I moved from Queens to Madhattan. In Queens we rented a row house which was like living in a mansion by NYC standards. We even had a backyard.
But living in Madhattan required a serious downsizing where we got rid of two thirds of our possesions. Where we lived was poor enough that having a stoop sale was not economically feasable, so we just put out our surplus out on the sidewalk with shopping bags with a free sign and by dinnertime everything would be gone.
Donating clothes and furniture required me doing lots of legwork because all those non profits are all short handed. After calling the Salvation Army we waited over three weeks for them to pick up all the furniture we wanted to donate, and this was after a season of record flooding in New Jersey.
I also discovered that this young girl who worked full time at a public storage facility was homeless, so we made special arrangements for her to get as much stuff as she wanted for when she found an apartment. At that time she had money saved but would have had to sleep on the floor. Today she has her own apartment and is applying to graduate school. Yes this college grad was homeless living in a shelter in Brooklyn and working in Madhattan.
Anyways I always say, "I never knew anyone with a complicated life that was happy." I worked hard to make my life simple. In this recent downsizing I learned that I really didn't need a lot to be happy, I learned that I am very fortunate, and I learned to appreciate fully the things I have.
It would be truely wonderful to be able to help make a better world. Basically we already have started.
Cal