Lots of good suggestions. Definitely the Liaden series.
I really loved the Lt. Leary series (most are available on
The Fifth Imperium - The Rising Tide cd).
Stephen Hunt's
Sliding Void series - really novellas
Allan Cole & Chris Bunch's
Sten series - Got mine at Fictionwise, but should be available at Amazon, etc.
James S.A. Corey's
Expanse series