I was going to say Star Wars Supremacy, but Homeworld really grabbed me by the nuts, I have to say.
I just LOVE the initial fly past opening sequence as the ship powers up for its maiden test flight. "What a beautiful sight" ... And even though it's old, the music and the lighting... *sigh* you really get this sense of being attached to the old girl. Later developments got to me even worse, but I shan't spoil them. Play it for the story if nothing else.
Relic should be the next strategic partners for Obs. They really do quality games.