Dystopian thriller for fans of The Hunger Games

I bet you'll think of The Hunger Games if you read Divergent by Veronica Roth. In a future Chicago (check out the skyline on the cover), everyone is divided into five factions: Abnegation, Amity, Candor, Dauntless, and Erudite, each of which values a certain character trait. On your 16th birthday you undergo an aptitude test, and then you're given the choice of switching from your birth faction to another one. And that's what Beatrice (Tris) does - she leaves the safe but boring selflessness of her Abnegation family for the wild, fearless Dauntless. A big part of the book is about her initiation and the intense physical and mental tests and simulations she and the other initiates have to go through - not all of them will make it. And in a sub-plot that's minor up until the end, Tris learns that the Erudite are planning a war to take over the Abnegation faction, and they have a plan to get the Dauntless to do their dirty work. Be warned that the violence is more graphic than The Hunger Games, but the tone of the book and sense of fast-paced survival is quite similar.