WARNING - Spoilers ahead.
It's a fair while since I've just sat down and read a book. If you can read a book without breaks except for meals and using the toilet, then that says something good about the book. The Fault in our Stars tells the story of Hazel and Augustus, a teenaged couple facing the fact that we are all going to die and the universe has no inherent meaning and that they in particular are going to die soon due to cancer. In a sense it's pretty morbid, but they remain surprisingly upbeat for people who find the whole "dying with courage" to be a load of trite nonsense.
There are three things in the book I can think of that, in my opinion, deserve criticism. The first was the tendency for scripted dialogue, e.g. a argument in the opening pages about attending support group:
Me: "I refuse to attend Support Group."
Mom: "One of the symptoms of depression is disinterest in activities."
Me: "Please just let me watch America's Next Top Model. It's an activity."
And so on. It communicates what is being said, but at the same time it feels a bit lazy to me.
The second is that the pace of the story is not really very clear. It'll skip a week or so, then go into detail about a single day, and there's nothing wrong with that but it makes the whole relationship feel very rushed, even though it is apparently happening over the space of several months. Perhaps this was a deliberate stylistic decision - the novel is at the very least influenced by Romeo and Juliet, the most rushed romance of them all - but it still feels a but jarring when Augustus invites Hazel to come to Amsterdam with him when they've known each other for barely 100 pages.
Finally, even though the novel is written in the first person, from Hazel's perspective, I don't feel like you get a great view of what makes her an individual. Maybe it's just my lack of emotional intelligence shining through here, but while you can easily paint Augustus as a playful teenager, old beyond his years, given to dramatic monologues and gestures, who would be right at home in an Oscar Wilde novel, it's far harder to paint a picture of Hazel. There's morbidity, and there's a fear of hurting others and an acceptance of social exclusion, but in her speaking patterns and her desires it's difficult to see her as tremendously different from any other teenage girl.
With that said, what in particular do I wish to compliment? There are some very nicely turned phrases; Green does an excellent job of making you care about the characters, they're believable and interesting. The pre-funeral is a wonderful scene, if a bit cheesy. Dying is represented painfully accurately.
All in all, I'd definitely recommend the book. I've spent a lot more time dwelling on what I didn't like, but I think that's more because in general the novel is consistently enjoyable and worth reading.