This challenge could have had many, many books attached to it. I'm always crying while reading, be it the death of a favorite character, something bad happening to an animal, or one of a million other things. So I picked the most recent one to make me cry and one from my youth.
A Monster Calls affected me deeply. My mother died a few years ago from breast cancer. She was my hero, my best friend. This book ripped those feelings from my soul and forced me to face them again. I literally sobbed in the break room at work. Thankfully my co-workers are used to my scenes!
Flowers for Algernon was recommended to me as a teenager by my best friend Sarah. I'm fairly sure she did it so she wouldn't be alone in bawling over it on the school bus home. This book broke my heart and still continues to do so. My father was recently diagnosed with Alzheimers. Watching him fail, and knowing with a pretty good degree of certainty that I will too, has made me think of this book often in the last few months. It would be bad enough to begin to lose you mental faculties, knowing what's happening as it happens would be devastating.