Matched

Matched by Allie Condie
Matched is about a girl named Cassia who lives in a futuristic society.  This society controls everything it's people do and for all of her life, Cassia has accepted that.  Then, she is Matched (married in a sort of way) with her lifelong friend Xander but for some reason, an unusual new boy named Ky gets tangled in their relationship.  Cassia discovers many things that she has never realized about her seemingly perfect society and now she has to make decisions that will change her life forever.
Also, if you have read this book already, look out for Crossed (already came out) and Reached (coming out soon).

Divergent

Divergent by Veronica Roth
Divergent is about a girl named Beatrice who lives in a futuristic Chicago.  There, the city is divided into five factions: Abnegation, Candor, Erudite, Amity, and Dauntless.  When teens become of age, they must chose which faction they devote the entire rest of their lives to.  Beatrice ends up making a decision that surprises everyone, including herself.  In the highly competitive initiation that follows, Beatrice, now newly named Tris, struggles with harsh training, brutality from the other initiates, and a possible relationship with one of her instructors.  During this time, she becomes transformed into someone that she never thought she could be and she realizes that in order to save herself, she must become someone that she is not.