No Jacob. Haha, just kidding. Without him, there wouldn't really be other books, or any "bumps" in the road for Bella and Edward's relationship. But out of the entire series, if I had to choose, probably Reneesme. I'm sorry, but I did not like Breaking Dawn as much. It was just wild and crazy and not the Twilight Universe that SM wrote when she was writing the first three. It felt like reading fanfiction.
I like Jacob and I'm glad him and Bella are friends, but I would change that when she was human she never fell in love with him. It complicated things to much and was hard on all of them.