I loved this book so much that I'm having a hard time formulating a coherent review. 
 The prose -- amazing. Authors, please pay attention to this. This is what you should be striving for when you write in first-person. It has a voice, it has personality. It pulls you in. 
 Characterizations -- spot-on. Beautiful. Haunting. 
 It's an emotional read. It takes you back to your school years and makes you think about things long buried. It made me feel like I'd actually been comparatively lucky -- I'd been teased off and on throughout my school years, but I fought back, and I never turned into one of the "mean girls." Despite all the crap that happened at home...at least I didn't take it out on other people, and I was never singled out and repeatedly made a whipping-boy, and I somehow had the ability to defend myself when I was teased. 
 On the flip-side, it was rather painful when I got to thinking about what my peers must have thought of me back then, the kid trying to hide the secret of her compulsive-hoarder parent. (view spoiler)[Of all the characters, I think I liked Sam's little sister the most -- she's probably what I would have been like if stuff at home hadn't been so awful, if I'd been allowed to actually be a kid and have a childhood. (hide spoiler)] 
 My only minor complaint is that Kent felt a little too unreal, too perfect. I'd have liked to see a flaw or two in him. (view spoiler)[But, considering we're seeing him through the eyes of our narrator -- maybe that was intentional. (hide spoiler)] 
 (view spoiler)[The ending was pretty sad...because her last day was so perfect....but it wasn't her "real" last day. Her "real" last day, she'd still been mean and horrible to the people who mattered. And that last, perfect day, never happened for the people she left behind. Back in the real world, her friends and family are left with those awful last memories, and Juliet is still dead. (hide spoiler)] 
 (view spoiler)[One thing in particular that I really loved, is that even in the first chapter, when Sam is pretty horrible and nasty, there are still these little seeds of goodness, of depth, scattered throughout. You think the same thing that Kent says to her later on, something like, "You're better than this." (hide spoiler)]