This is a very hard book for me to review.First things first - I loved the characters. Brittany and Alex are both loveable, relatable and sweet heroes. Their interaction was one I loved to see, and their voices were both strong and real. They're definitely people I'd like to know in real life, and their stories, while truly sad, also rang with a lot of hope and strength. Most YA books I have read recently dwell too much on the character's inner self-evaluation and little on their interaction with others, as if the writers thought that angst is all there is to a teenager. Perfect Chemistry is quite the opposite, and it's good to see that the characters don't need to add up three apples and the square root of Pi in order to explain their motivations.Also, it's important to say that this isn't just a script for a chick-flick waiting to happen. The author deals with some very unsavory and sad aspects of life, and does so with as much tact and maturity as the subject should be approached with.However...First of all, let me make this clear - predictibility is not a flaw. Hell, I think I prefer a cliched plot to one where it looks like the author was on LSD while typing. Events, character motivation and secrets that look like they were just pulled out of someone's ear, that's not my cup of tea. If you want an unengaging, straightforward book, then Perfect Chemistry is the thing for you.The problem is that it falls just a little flat. The characters are vivid and spicy, but stereotypical. The story is heartbreaking and heartwarming, but predictible. Three chapters in and you can imagine how the plot will develop. In execution, it is very funny and entertaining, but in that way a good fanfic is funny and entertaining. It's lovely, but it can be better.Still, it's a pretty solid read, so I give it three and a half out of five. I'm happy to say that the second book improves.