People look at me strangely when I say this, but there is no way in hell I would want to win that kind of money. It changes things forever, and I don't think for the positive. Relationships get destroyed. People go broke because they don't know how to be rich. You think you will do all these wonderful things, but you are just as likely to lose all motivation in life because you don't need to do anything, you have no responsibilities. You'd be much better off winning low and taking the yearly payout. You're comfortable, but can't be ridiculously indulgent.
That's why I said the first thing I would do is take most of the money and put it somewhere that I can't touch it. I would have it pay me a stipend each year. Essentially, I would pick a number that's low enough to motivate me to work without requiring me to rely on the job (I would have that stipend increase dramatically upon reaching the age of 65, though).
The only way I could touch the rest of the money is if I give it away to a non-profit or public interest group or if I need to pay for some kind of medical emergency. In other words, the money is a safety blanket, not a life-altering event.