Since you can vote for for multiple charities, there's no reason (apart from your personal feelings about the individual charities, of course) to not also vote on the following (the last two are Givewell rated charities):
Why does the Givewell link say "Clear fund"?
http://www.reddit.com/donate?organization=582565917
"Today we are announcing that we will donate 10% of our advertising revenue receipts in 2014 to non-profits chosen by the reddit community. Whether it’s a large ad campaign or a $5 sponsored headline on reddit, we intend for all ad revenue this year to benefit not only reddit as a platform but also to support the goals and causes of the entire community."