My friend described this series "addicting," and it sure was. Please, don't read this series if you're looking for some literary analysis (although maybe if I think hard enough, I'd come up with something). The series is just fun. All the books on my reading list went down in priority so I can finish the Twilight Series. I read New Moon, Eclipse, and Breaking Dawn one after the other in the past few days. The books get better per volume.
In New Moon, Jacob's character was fleshed out better. He is a more three-dimensional character than Edward was. He has more warmth to him (too much!) and has more life, as against Edward's being morose all the time. The novel seemed disjointed, though. The first half was happier, I suppose, because of Jacob. The second half, when Edward came back into the picture, seemed too far away, not just geographically, but also in tone.
Eclipse was better, since it played out the love triangle with humor. The novel allowed the characters to bounce off each other. It was the most natural of the novels. The big bad vampire that comes to destroy their happiness, though, was not too too interesting. But that was okay. The novel was fun, and you know that she's saving the Volturi, the big bad guys, for the final showdown.
Breaking Dawn had the potential to be the most exciting of all the novels. The first 1/3 of the novel, I thought, could have been shortened. I'm not interested in the details of the huge wedding, or their fabulous honeymoon in a remote island. It begins to pick up after that, especially when the novel starts being told from Jacob's point of view. It all built up to an ending that was satisfying enough, but promises so much more. There were new characters introduced. The plot continues to thicken.
There's a promise of so much more. To end the series here will shortchange all its followers. It will be a shame if Breaking Dawn was the last novel (Midnight Sun doesn't count, since it's just Twilight written from Edward's point of view).
I wouldn't say this is the best vampire series I had ever read. Others, and I'm thinking of the Anne Rice novels, had much more layers; more ideas to ponder; had more intricate plots and mesmerizing characters. Don't try to look too closely at these novels, or you'll find the cracks. And if you do, you'd just be denying yourself the fun and entertainment the novels can provide on a lazy Sunday afternoon.