If you are in any way a Gears fan you have to read Karen Traviss books. The four books make up all the backstory the games don't give, and act as a prequel for Gears of War 3.
I do not understand how people will know whats happening in Gears 3 without reading these books. And Traviss is a really great writer not just some hack hired to churn out a fast tie in to make a buck from fans. Epic games have trusted her to guide the course of all Gears property's with her storylines. The book Coalitions End moves at a fast pace with action and political intrigue to rival Tom Clancy. It details how Delta Squad mates came together after E Day and chronicles the events leading up to the epic final game.
Questions left unanswered in the book will be resolved with Gears of War 3 and I for one can't wait