I'm not going to differentiate between a little, a bit and a lot. These books broke my heart in some way - some of them managed to put it back to together, some left the scars still showing, some left it shattered forever more.
It was not easy to pick these books, though. Some were obvious to me, recent reads, those that really changed the way I see things. But like with everything else, time is a great healer, so it was hard to look at a title and figure out if that one broke my heart, and how it did so. With that in mind, this top 10 will not have 10 books. Oh, and it will probably have loads of spoilers. Proceed with care.
The Book Thief by Markus Zusak
This is one of the freshest ones in memory, and in heart. It took a while before I had the courage to pick this book up - after all, it's set in Germany during WWII, heartbreak was bound to happen. But the amount of it was just... too much - deaths (oh, Rudy) and tragedy, and the strength of the main character - it all left my heart in pieces, and I'm still nursing it.
Plain Kate by Erin Bow
Plain Kate was another of last year's books that broke my heart. The story was sad, but what broke my heart the most was not what happened to Kate, but the antagonist of this story, whom I loved almost as most as Kate. And then there is Taggle, but at least with him, my heart was able to heal a bit.
Son of the Shadows by Juliet Marillier
This is a book that I read for the first time oh, so long ago, but reread it a countless times since. It still shocks me to see a beloved character go, and Sorcha's departure is simply heartbreaking. But this is a case of a book that helped me grow, and be who I am.
La hormiga que quiso ser astronauta by Félix J. Palma
The way this book broke my heart is different from all the others - it didn't kill some beloved character or made love simply unattainable. It shattered my illusions that life can be magical. Surreality was just part of the main character, a Peter Pan complex of not wanting to grow up. And I can relate to that on so many levels...
Everything is Illuminated by Jonathan Safran Foer
Another one dealing with WWII, and the hatred and prejudice that lead to it. The story is poignant, with silliness in the mix, which doesn't help soften the blow. It breaks my heart, and tries to mend it with laughter, but never intends to hide the scars it leaves behind.
Oath Breaker by Michelle Paver
Oath Breaker is the last in this list, and more of an afterthought. I read it some time ago, so time has helped me forget, but it's also a book that managed to heal my heart along the way. It starts by killing a character I learned to love - Bale - and that was part of why it hurt, it was not an instant-love kind of character, there was time and suspicion and surprise devoted to him. And of course, this death had its consequences - especially with Torak who felt the loss as I did, and the guilt that I wanted (so much) to pin on him. But it made the character grow, and he never once forgot what lead him in his quest, even if he came to realize that guilt and hatred and revenge were not doing him any good.