Each year around this time, GiveWell, a respected organization dedicated to analyzing charities, issues a list of the handful of charities that represent the very best "proven, cost-effective charities for helping the global poor." Their recommendations come after a thorough vetting process. Dollar for dollar, you can do the most good for the most people by donating to these charities. Here is this year's list (which is very similar to last year's list):
The trend here is clear: the most (cost) effective anti-poverty charities are health programs that can do a lot of good for a relatively small amount of money, and direct cash donation to the poor. GiveDirectly's model often provokes skepticism about whether or not the money will be put to good use by the recipients; lots of research says that it will. If you want to look at GiveDirectly's internal data yourself, you can find it here.