Give half (or possibly less) to select charities, buy a nice house somewhere in England, Get a nice car, possibly go to college, then use what's left to support my family and myself in the future, never having to work again, and allowing my kids to support themselves for the next few decades, allowing them to go to college and raise a family of their own.
And keep my super-duper-mega-damn-amazing-gaming-computer-from-heaven updated with the latest hardware, software, and such.
I wouldn't give too much to a single charity.
Power corrupts. Absolute power corrupts absolutely.