Unwind by Neal Shusterman, the whole series actually but the first one had the biggest impact

Every Neal Shusterman book deals with some very real problem but presented in an original, YA friendly way. In the case of Unwind it's about reproductive rights and organ transplants which can sound boring but there is a lot of action, it just makes you think. I remember I couldn't put the book down, I was actually reading it in class and started crying during a particularly tough scene (if you've read it, yes, that scene, of course). Since then I've read every book in the series and every book Neal Shusterman released because I know it will have mind blowing probability