The book that made you so emotional

What makes a book good? This is on my mind a lot ! What draws a reader in to loving a book. I have come up with this the characters have to be lovable. Second I look back at the books I fell in love with and what made me fall for them. I remember one book specifically "Suzann's Diary for Nicholas" by James Patterson. I was in my early twentys back when borders was still around. My relationship status well it wasn't a great relationship at the time. But the book was about girl that fell in love with a man that lost his family in a car accident, except he didn't tell her about the car accident or that he had a one year old that died. he wasn't fully over his family, and she was heads over heels for him. He keeps Leeding her on and ditching her at times with no reasoning. I won't give away the books ending but, James Patterson is known for his mystery's and for a love story with a twist of mystery to it ... This was one of my favorite books. I remember sitting for hours reading this book at the end of it I was crying ... It was close to 10 pm and I cried so hard learning the end of the story. I guess I was trying to relate my own bad relationship to the charters in the book, hoping that maybe there was reasoning to my own relationship at the time. That book made me keep reading trying to find my perfect love. Until I did.