Well, it all depends on what exactly you would like me to share

Fund research about how to stop aging in human cells.

It's gonna get done eventually and I want it to be during my lifetime.

Spent a fortune on help the "Good politicians" to Win against the corporate funded politicians and then help with rebuilding a society that makes life Worth living for everyone, if you have 2 cows, but your neighbour doesn't have any cows, the society will encourage those who have what they need to share what they do not need with people who needs it more, therefore you will give away one of your cows to your neighbour so that he can feed his family. Creating a industry that helps people as well as helping the nature, like a symbiosis between us and nature and turn it into a economical source bigger then Oil, so that we can take away the power that certain people can maintain by keeping the world addicted to Oil. There is a lot of things i would do and i wanna do a capitalistic-socialism campaigne, where we earn money through capitalisme but the fortune is spent socialistically and equal to everyone who needs it, including free health-care and education to help those who can't afford it to be able to get away from poverty and live q honorable life Worth living

Hahahah. Ok, you could have a room for yourself, one or two cats, and... Andrew Garfield or Ian Somerhalder. That´s how altruistic I am

I would do something like the book Foundation describes, save the world's culture, languages, science, etc. in one place in case of disaster (including self destruction or massive environmental destruction). Massive bunkers, that would be challenging to get full autonomy for hundreds of years, perhaps underground farms, stockpile of petrol, components, why not a zoo, call me Noah, etc. and we'd spend time composing poems, listening to music, reading books, lazily waiting ah ah
Not that serious, but I can't really imagine "changing" the world in a meaningful way. I mean if we go in the right direction, Africa will develop, diseases will be cured, but if we go in the wrong direction, and I think we are... here I am for the second round ! A second chance for humanity, that would change the world... perhaps.

I would buy up that beautiful old building down town and turn it into a state of the art IMAX theater.
Oh to change the world? Build and invest in solar farms probably. Dunno really, would probably be too busy enjoying myself with the latest gadgets and learn to fly.

Great! I could see if their WiiMote are well calibrated e.e

Bah, screw trying to change the world. I would rather focus on improving the economic stability of my country. At current it is on the decline with jobs being exported and items being imported.

I would have funded research into ocular replacement technology. For utterly selfish reason of course.

Would also bought a complete collection of Nintendo-games