I quite enjoyed Supreme Commander's campaign, not so much for the story, but for the way the battlefield would expand as you complete objectives. Rather than be in the same theater for 5 - 6 missions and having to rebuild your base from scratch each time. Also, the scale of the battles you could have in the end game was impressive. As the battlefield would expand, so would your unit cap. You'd start with a cap of 150 buildings and units and by the end of the map it would gradually expand out to 500 buildings and units.