What is the best science fiction for people who serve in the military?S

There are many debates over the best and most realistic military science fiction. But those arguments are never about the best science fiction to read or watch if you're actually serving in the military

We know a lot of io9 readers have been in the military, and some of you are on active duty right now. What do you think? What kind of SF gets you through the day (and night)? Do you want realistic military SF or escapist supernatural romance? Or something totally different?

Tell us in comments! Let's put together a list of must-read and must-watch SF for people who know the military first-hand, and not just from stories.

U.S. Air Force photo taken by Tech. Sgt. Efren Lopez