For reasons too stupid to go into here, a lot of people are either boycotting or buying Tor books today. I come down on the "buying" side of this debate, and since I've already told you about The Incrementalists, published by Tor, I shall tee off on another of their fine books.
Redshirts, by John Scalzi, has a premise so good it's surprising it hasn't been done before. On the starship Intrepid, nothing permanent ever happens to the bridge crew. No matter how many times they travel to a hostile planet or take on a warlike alien race, they come out fine. But at least one member of the ground crew, one of the seemingly endless ensigns, always dies. Andrew Dahl is a new arrival on Intrepid and learns this fact of life, then organizes the others to find out why.
Scalzi takes a jokey premise ("Hey, what's with all those guys getting killed whenever Kirk goes to a planet? And what's the deal with airline food?") and spins it into something truly wonderful. Redshirts would be excellent if it were simply a meta action-comedy, and this section of the book reminds me of Terry Pratchett in its escalating stakes and logical leaps. But it's the codas where I feel Redshirts truly shines.
The original full title was Redshirts: A Novel With Three Codas, and the final third is made up of three short stories about minor characters from the main narrative. By the time the codas are done, what was an amusing sci-fi story has become something much different, something deeper and more meaningful. I can't really describe why without spoiling the story's surprises; all I can say is it hit me pretty hard, much harder than I was expecting. There's a reason it won all those awards is what I'm saying.
I also recommend getting this in audio; it's read by Wil Wheaton, who, in addition to just being really good at audiobooks in general, lends the story an extra level of metatext just by showing up.