I am a Space Opera fan so these might not be MilSF enough:
*Jean Johnson's Theirs is not to Reason Why series is Mil heavy. The story is based around a precog who is combating the end of the universe so it may annoy genre purists. Starts with
A Soldier's Duty.
* Mike Shepherd/Moscoe's Kris Longknife is a a Space Opera/MilSciFi fence sitter. The earlier books being far more Mil and the latest more Opera.
Mutineer is first.
There is another about a female space marine that is slipping my mind at the moment -- I thought it was Vatta's War by Elizabeth Moon but that isn't it. Maybe someone else will remember. This series has some high pheromone humanoid aliens in it that could cross the romance scene ick factor for some readers. (Vatta's War is more pure Space Opera IIRC.)
Edit: Found it, Confederation by Tanya Huff starting with
Valor's Choice. A new series/book in the setting just came out.