I had wanted to read this book since I heard that the writer had gotten tired of the "manic pixie dream girl" trope and wanted to destroy it. I don't remember where I had originally seen it, but I did find this article that supports that thought, spoilers are in the article though.
I loved it. I love the way he does it, which is really hard not to spoil, but I'll leave it to you find. He just humanizes the MPDG. By the way, if you are unfamiliar and don't want to spoil the book with the other link, try this one out, it's the Wikipedia page for the term.
All the friends were brilliantly written as were each set of parents. Of course, the protagonists parents were the best. They reminded me of the parents from Easy A. I wasn't so sure about John Green, I'd seen The Fault in Our Stars and didn't feel the need to induce that much heartache over fictional people again (so I can't even bring myself to read the book, though I'm sure it's even better). You'll notice in the article cited above that Augustus was even supposed to be a manic pixie dream boy (whose manic and dream states get summarily torn down as well, but it isn't the point of that book, so I don't think I spoiled anything there). Anyway, I'll probably read some more of his stuff, particularly when the point of his books, overall, seems to be humanizing those experiences in our lives that have broken us down into tropes and two-dimensional characters.
Loved the book! Gonna watch the movie later this week, I think, too.