The 2008 TIME 100

"From what we get, we can make a living; what we give, however, makes a life." —Arthur Ashe

Arthur could well have been talking about Andre Agassi. We are all aware of his tennis accomplishments, the brilliance and flash of his career. It's impossible to forget his epic U.S. Open victories, and also—though he might want us to forget—the mullet and acid-washed jeans. But the greater challenge for an athlete is to have a positive impact away from the cameras. I've been privileged to witness firsthand Andre, 38, do just that.

When I was 17 years old, we were on a flight together. I was very nervous, but Andre was kind and encouraged me to ask him questions. When I asked about his biggest regret, I expected some answer related to our profession. Instead he said it was not starting his charitable foundation earlier. I was shocked that a person who has set such a high bar for athletic philanthropy still felt like he could do more. But that is Andre.

There are most likely plenty of kids at Andre Agassi College Preparatory Academy, a model K-12 charter school for disadvantaged children in Las Vegas, who have never watched a match of his. I promise you that Andre could not care less. He would rather be viewed as the man who gives them dreams and opportunities.

Roddick is the No. 1 U.S. tennis player