B is for Brothers
The sibling relationship really drew me into the story because my sister is my absolute best friend. In a lot of books I've read, I tend to wonder if the author ever had siblings because their interactions just seem...weird or strained or hateful. Even though Jacob and Will rarely saw each other because of Jacob's life in the MirrorWorld, their relationship felt genuine and it was a huge driving part in the story. Jacob's love for his brother made him desperate to try anything to save Will from turning into a Goyl, and I know I would have risked anything for my sister. I'm not a huge Jacob fan (it's not unusual for me to attach myself to a side character and be kind of 'meh' about main characters. It's nothing personal, Jacob. You're still a great MC) but I did truly love his determination and refusal to accept failure even when things turned dark with his brother, and that brotherly love is one of the many, many reasons this book has reigned number one for five years (and probably a lot longer) for me.