Good Military Sci-Fi Books? Appreciate Recommendations

Gnomon:   I was hesitant to try a Halo book when I first saw it, but the Fall of Reach was pretty good!    I would recommend:    The Remaining - More post-apocalyptic than sci-fi, but it's about a Captain in the US Army trying to survive some zombie-like things.   Warship - Faster-than-light travel + new enemies = ???   Terms of Enlistment - Main character enlists in the armed forces and stuff goes down.    They aren't the best or most fulfilling books, but they're pretty entertaining.