I'd buy my parents new houses, quit my job and travel the world the rest of my life. I'd buy a huge house in the country, go around and adopt all the animals out of animal shelters and hire people to play with the animals all day. Probably would try to run a few of my own businesses. Set up college and trust funds for my kids.
I'd hire instagram "models" and fly them to Dubai so I can piss on them and buy them Louboutins (those red bottomed shoes all the hoes wear).
See, that kind of money is just unthinkable to me. Buy my entire family houses and cars? Pay off everything I've ever owned? Set up trust funds for everyone? Okay... now what do you do with the other 180 million bucks? After a certain point, a human being has everything they need to survive comfortably, and be content in day-to-day life. I would put most, if not all, of the rest (after the aforementioned expenses) in the safest investment I could (T-Bills, blue-est of the blue chip stocks), move to someplace rural that I could have every creature comfort I could want, and still be somewhat close to civilization. I would go to school. I become a professional student for a while. Not so much going for degrees, but learn for the fun of it. Oh and I would set myself up a Vegas fund. A certain amount per year that I would allocate for myself to go Big Pimpin in Sin City and live like a Whale, being wined and dined by the casinos for my action, and being hedonistic for a couple of weeks a year. Then go back to learning and living.