Homeworld II is a really good real-time strategy game. It is space-based, so your commanding fleets of ships (from little fighters and bombers to big battlecruisers). It also has a good plot, and I personally adore its music. It gives off a somewhat Dune-like vibe.
It may be a bit too combat-oriented though.
I am sure you know the next Total War is coming out. So that would be another one.