I recommend Before I Fall. 
 ...and here I thought I finally got tired of Lauren Oliver's writing... but I'm glad to have read Before I Fall. =) 
 There are 7 chapters, one for each day that Samantha Emily Kingston gets to live again. Let me tell you that each chapter is very long, thus the book is thick. Which discouraged me to finish at first, because contemporary books should never be this long. Right? 
 Chapters 1-5 are not interesting. Chapters 6-7 however, these are different. In fact, these made up the 4-star-rating I have up there. Sam's realizations made me think, made me ponder on how the lives of people around me are affected even by my little actions (or inactions). 
 If you have 7 chances to live one day in your life, what would it be? Sam didn't get to choose the day, but she did everything, anything to get out of the weird time loop. When she's on her 5th or 6th day of repeat, she wondered: perhaps she's not meant to save her own life..? 
 Oliver's writing is not as impressive to me in Before I Fall, but the emotions are still there. Want. Cruelty. Guilt. Selflessness. Redemption. There are reasons why mean girls are mean. 
 It was a heartbreak to know that the fleeting moments Sam had with Kent McFuller are just that: fleeting. Their story was tender and sweet when wrapped up in the end. 
 Before I Fall is not on top of my Lauren Oliver books, but the last two chapters got me reading and re-reading those exchanges between Sam and Kent. *sigh* Yes, I'm mushy like that.