The TIME 100

Success can be defined any number of ways. I personally have always defined it as waking up every morning with a smile, looking forward to the day. Is there anyone who embodies this definition more than Richard Branson?

I can only imagine that the man falls asleep at night dreaming about what adventure he may undertake next. Business isn't what he does for a living. It's a playground where he can live out every dream and idea as if engaged in a sport, one where winning is creating a business that others thought impossible. I have no doubt that he takes great joy in the ride against the grain of traditional business—and that he feeds as much on the puzzled looks of those who do things because they have always been done that way as he does on the entrepreneurial energy of following through on his visions.

Virgin Galactic, Richard's foray into commercial spaceflight, may seem like the ultimate quest. A final stamp on an amazing career. It won't be. He will hear about something that everyone else thinks is outrageous and make it a reality. That's who Richard Branson, 56, is. I have no doubt that when Richard Branson dies, he would want to come back as...Richard Branson.

HDNet chairman Cuban owns the NBA's Dallas Mavericks