I'd make video games. And if the FU money was sufficient, I'd donate the profits to charities. In fact, maybe I'd even setup my own charity and fund it through the sales of games.

One thing I'd really like to do is setup an outdoor walking/running/cycling/dog-exercising area. Maybe buy a big area of land/forest or something, and then setup various different trails. I'd try and make it a real destination for people who want to enjoy an active lifestyle. The trails would be separated to some degree too, so cyclists wouldn't be on the same trails as walkers/runners, and dogs could have an off-lead and on-lead trail and so on. I'd hold events throughout the year, 10k charity runs/cycles and the like. There would be good facilities on site too, so you can have a shower, get changed, buy some good food and so on.

Yeah, I'd really like to do both those things.