I went to Ethiopia last year, and we worked with A Child's Right, which is now called Splash. They focus on water filtration, as it's a very cost effective to install and maintain clean drinking water.
We also worked with The Selamta Family Project, one of the most successful
I'm actually not able to go back this year, but my sister has an opportunity to go there, and she'll be meeting with all the great people I met.
My brother is also heavily involved with Not For Sale, a highly effective anti-slavery and anti-sex trafficking organization.
There's all kinds of good stuff going on in with those 3 organizations. Seriously, check them out.