-I-War. It is 11 years old.
I-War 2: Edge of Chaos is (c) 2001, and it's still a decent game. But, the playable ships are only corvette-size, so it might not be exactly what you're looking for.

You might want to check out Nexus, if you can get it for cheap. It's a tactical-level space combat simulation (about a dozen ships per side at maximum), and the combat system is somewhat detailed with lots of subsystems, different damage types, power management etc.

The downside is that it's very linear, as in almost zero replayability.