| Forever War by Joe Haldeman
The Last good SF book I read was The Forever War by Joe Haldeman. Joe wrote the FW after coming back from Vietnam as a Combat Soldier. The FW is one of those books that, I believe, we will see less and less of. It is a SF, but its greatest impact is social commentary. In fact, when Joe wrote it after the war (Vietnam), it was immediately published and did very well. It was read by a large number of mainstream readers and has been highly regarded ever since. In fact, up until recently, the book was missing two original chapters that the publisher thought would offend people at the time (see John Kerry in front of Congress in the 70's). Joe landed a job at MIT teaching creative writing.
When I started FW, I was not too impressed. Joe writes like Hemingway, in short declarative sentences. What kept me reading was the content. There are several unique things about this book: The drudgery and lethality of boot-camp, women in combat, the free sexual relations between the soldiers, the fact that we never see or understand the enemy, and finally, through time-dilation, we experience the absurdity of war in a way that reminded me of All's Quite on the Western Front.
By the time I'd finished FW, I'd gone from not impressed, to emotionally moved. I wrote to Joe and congratulated him on the FW, a high point, socially relevant addition to outstanding SF.