That’s why the Gateses are No. 1 on our 2010 list, which, like last year’s, we developed with Global Philanthropy Group, a top consulting firm. This rocketing from No. 7 isn’t the only news. Ten new members have joined the roster of 25, including a bicycle magnate who is giving away tens of thousands of bikes across Africa and a movie star who has launched a social network that amounts to the Facebook of philanthropy. The repeaters on the list, for their part, have done plenty of good work over the past year. And, for the first time, China is represented on the list, as the American tradition of philanthropy continues to spread around the world.

This article originally appeared in Barron's