I think the best part of homeworld was the campaign, the cut scenes, voice acting
The ending of Homeworld 1, and followed by the Credits, (Ladder), really made it feel Like I have finally beaten the game, and felt great after.
I never really gotten into the multiplayer games for homeworld. Campaign was great and I have replayed it a few times. (Hw->cata->Hw2 order)
The campaigns for these is a must play(it will keep you busy for a while). Maybe I will play it again right now.
Oh and of-course, the reason why this game beats campaigns in other rts games in my opinion, must be the fact that you can keep your fleet when you move onto the next mission!! WOOOOOOOOOOOOOHOOOOOOOOOOOO