I just played "Klingon Armada" for the first time last weekend - a really enjoyable, light-weight combat game from the SFB people. I've also enjoyed Attack Wing a lot lately - just play casually and stay away from the tournament crowd. Starfleet Battles and Federation Commander are both heavier than what I currently want to play, and the FASA game never seemed balanced - weighted very heavily towards the Fed ships.
Attack wing is quite fun - misses out some of the granularity of differentiated weapon times but the maneuvering is quite fun!