When formulating this list, there were many runners up which failed to be either internalized into my character or to be truly great. However, each of these I would heartily recommend to anyone.
These books meant a lot to me in my formative years. The world Cornelia Funke created in this trilogy has stayed with me well into adulthood. The second book may be my favorite. I read it while in extreme pain due to an ear infection. Subsequently, like her characters, I lost myself in the fantasy. Leaving the torment of my circumstances behind, I embroiled myself in the beautifully tragic narrative of a self-aware, fictional character who knows how his story will end. This book made me cry. The timeless premise of this trilogy enlivens my imagination even to this day.