Two stories from the past week that have received a good amount of coverage, but fit the bill for this thread:
Anthony Rizzo, who overcame Hodgkins-Lymphoma, just donated $3.5 million to a children's hospital - SBNation.com - Rizzo has been involved with this organization for at least a couple of years, and there are many accounts of him being great with the kids, staff, etc. This donation is the culmination of a long-term relationship.
https://www.forbes.com/sites/kellyph.../#7b8c1c975cbb - little outdated, as I believe Watt's fund is now past 17M. But also some good info here about how the funds are being allocated without incurring substantial overhead.