the Star Force novels by BV Larson (awesome books)
the Doom Star series by Vaughn Heppner (also awesome)
The Spinward Fringe series by Randolph Lalonde
Odyssey One by Evan Currie
The Nameless War by Edmond Barrett
the Star Carrier series by Ian Douglas
Mecha Corps by Brett Patton (shapeshifting mechs in space)
these are the ones i've read that go heaviest on the action.
i see you've got a kindle. the original Spinward Fringe trilogy is a freebie on Amazon-
http://www.amazon.com/Origins-Spinwa...8938264&sr=1-4