The Fault in Our Stars, John Green
It's not so much that I knew what the sad part about this book was going to be, but just that I knew this was going to be a sad book no matter what, and that usually tends to keep me from crying when I read books, watch movies, all those things. So what brought the tears to my eyes was the timing. Whether you saw the Very Unhappy Thing in this book coming or not, I must say I felt Green's timing of it was pretty well done. That being said, I didn't do a whole bawling-my-eyes-out thing because still...it had to happen. You just knew it had to happen.
Wonder, R. J. Palacio
This was more of a steady cry than Fault was, but still not too intense, perhaps because they were tears of joy, which, I gotta give it to Palacio, has never happened to me before. So kudos to you for that! But yeah, I've raved about this book before so I won't go into too much detail. All I can say is that I demand you read it. It will very likely make you cry tears, but whether because of a Very Happy Thing or a Very Unhappy Thing I cannot say.
Harry Potter and the Deathly Hallows, J. K. Rowling
All I will say is I cried two times in this book, but the hardest was over a human death.
The Book Thief, Markus Zusak
I think this book is pretty obligatory for this list, but I gotta say it's definitely the most devastating turn of events I've ever read in a book. Perhaps that's not saying much because I don't read a lot of depressing fiction, but still. It's that feeling like a trap door. Everything you thought was there and all that you never before thought twice about is suddenly lost from you, that's this book. It's amazing and yet another I demand you read if you haven't already.
Where the Red Fern Grows, Wilson Rawls
This book takes the first because it was the first book to make me cry. But because of that my perhaps eleven year old self was put into this literal stake of shock. This is the only book where I've wholly and unabashedly shed tears, and not just tears but snot, sweat, and most likely a good fraction of my eleven year old innocence. It's an oldie but a goodie. Read it! (Preferably with tissues. Lots and lots of tissues.)