I primarily donate to SI (~80%), but I also donate to whatever Givewell's top charity is at the time. Over the last year this has resulted in $150 to VillageReach and $300 to AMF and $1800 to SI.
Why SI? Primarily because I like the people who work there, and wish to signal to them that I am part of their community and that I believe in their mission, so they will like me in return. :)
But that reason is not likely to convince you if you've never met them -- instead, consider that the work they are doing is incredibly important, and they're probably the best-equipped and best-positioned team to execute on any plan like theirs.
When I was a graduate student at the University of Notre Dame, I received a monthly living stipend of roughly $1,600. I decided to commit to giving ~10% of it to charity, and I had read in Peter Singer's book The Life You Can Save that one of the most efficient charities out there was Population Services International (PSI). Singer reported that GiveWell, a leading charity rating organization, had estimated that PSI's efforts saved lives at a cost of $650-$1000 each (pp. 88-89). So, I set up a recurring monthly donation of $160 to PSI, and kept it up for 15 months, for a total donation of $2,400.
I've been meaning to post the above information publicly for awhile, but was pushed over the edge by reading one of Eliezer's posts from a couple years back, Why Our Kind Can't Cooperate:
Since Eliezer's post is about rationalists, he stresses the issue of what arguments people voice. However, we know that just telling other people that you've given to charity makes them more likely to give. This is a point that Singer himself has emphasized.
I propose a thread for people to publicize their charitable donations. In light of the above, I'm especially interested to hear from people who've donated to the Singularity Institute for Artificial Intelligence. Once I acquire a regular source of income again in March, I intend to continue to primarily direct my charitable giving towards PSI, but maybe someone in this thread will persuade me to start giving to the Singularity Institute.