I have to say that this is probably my most favorite YA book series. I really loved the character development and the story progression throughout the whole shebang. As well as the whole gang - which is always a good thing.
Then if course there is Derek and Chloe's relationship. I loved how layered Derek was. It made things really interesting and made you fall in love with him a bit more and more as time passes... just like Chloe. I appreciated that they had a journey as much as the story did. Nothing that's "just at the surface" is better that something you have to work toward and build. I think that's why Chloe gravitated toward Derek, not Simon. I would go futher and say she never, ever truly liked Simon. When things where scary and when she needed someone to really talk to she sought out Derek and despite it all, he always came.
Popular culture references and snarky humor tie everything together into an enjoyable bow. This series is dearly loved and these awesome characters are truly missed. I write this review on my third time reading this series, with no doubt I'll read it from start to finish a few times more. It's just that good!