Someday, when I'm filthy rich (that's when, not if) aside from charity work I'd have to do a few specific things. I've thought about this before, naturally.
Apart from maybe a few more condos here and there, I'd have 3 homes to travel between.
One in Monaco, my city residence so I can see the worlds greatest F1 race every year from my yacht and because you need a base in Europe. The people there and the nightlife is just another plus.
One in Colorado, my private residence so I can have a quiet place to go and experience a great winter season skiing and snowboarding.
One in Australia just outside of Sydney, my beach front residence where I can go to wake up in front of the waves and catch some surf, a place where it's always nice weather or just never snows.
This is a nice spread across the worlds continents. Throw in a few vehicles at each place and some private jetting in between and you got yourself a lifestyle. As a filthy rich person I'd try and do things with my money that gave back to people. Invest in Green products/corporations, medical research, and throw in some consumer technology to make things fun.
For a hobby I'd probably try and buy a professional football (NFL Americano, for you kids across the pond) or baseball team. I would see about becoming owner or part owner of a racing team, F1 if I could otherwise American Indy cars would do nicely. Not NASCAR, my neck isn't red enough.