Paul Allen

Lifetime donations: $2 billion
Net worth: $17.3 billion
Generosity Index: 12%
Paul Allen, cofounder of Microsoft, now serves as the chairman of Vulcan, his private-investment company.
As chairman of the Paul G. Allen Family Foundation, he's given millions to global-health causes, including $5 million to Seattle BioMed, $4 million to Global FinPrint, a conservation project focused on the preservation of sharks worldwide, and $7 million in grants to Alzheimer's research.
Source: Wealth-X