There was an outstanding RTS game from 1997 called Total Annihilation. The soundtrack was 11/10, it was made by Jeremy Soule, the guy who did the Skyrim soundtrack. Some might say that Supreme Commander 2 is their most recent successor to TA, but they are wrong. Check out Beyond All Reason (BAR). It's in Alpha and it's free but it's already sooooo good.
I think most people that enjoyed SupCom1 didn't like SupCom2. The first game was leagues better, imo. There was also Planetary Annihilation some years ago, which was much simpler, then an expansion and I dunno how different that one plays.