John Scalzi - Old Man's War

This will probaby be my favorite book of the year although will have to wait and see.  Written with the DNA of Heinlein with some Ender's Game thrown into it this is what to me defines the genre.  A great set up that leads to even more crazyness.  Throw in the Ghost Brigade and wow what a great concept.  It will be interesting to see how the books down the line continue to carry the concept.