Various organisations and clubs furthering scientific development and education.
I found that most of world's problems are either caused by greed, poverty or a lack of education. Since you can't end greed or poverty by just pouring money on those issues, I instead donate to institutions providing free learning materials, open source software and other causes indirectly bettering the world by empowering the underprivileged.
I also spend money on the Free software I use. I contributed to a repository listing donation options and I'd be happy if others would also contribute: https://github.com/n1trux/awesome-donations
I donated to Wikipedia, and i bought the Simple Thank You to help support Tibor Kaputa who makes the Simple Suite of apps for android for free on FDroid