A popular sub-genre of science fiction is military SF. It is, as are many things, mostly awful. There are occasional startling exceptions however. I recently read Joe McDermott's The Fortress at the End of Time, from Tor, which is being marketed as military SF, and though this is true, it is true in a way that happily subverts any expectations or cliches.
The book, also quite short in a genre which encourages bloats and endless sequels, is a perceptively written first-person confession by a young officer assigned to one of the worst postings imaginable: a boring station in orbit around an ignored planet on the edge of subsistence. The plot concerns the implacable hostility of bureacracy, frustrating attempts to combat the sexual abuse of female soldiers, and attempts to stay uncorrupted in an economy based almost entirely on bribes, favours and patronage. The hero is a stolidly well-meaning but also somewhat priggish and naive man, very well drawn. Though the setting is military, there are no battles and no aliens. McDermott is also imaginative and rigorous in his future physics, and the book is a delight. Even the cover is nice: a lonely figure in a uniform looking out over a nearly dead world. There should be more like this.
To contrast this book with the competition, this is what military SF is normally like, as exemplified by the output of reliably ugly Baen Books (see more on them here and at the end of here), which publishes books for people who just want battles, spaceships with big guns, and aliens that are either dead, comical or in possession of enormous breasts.