I am a really big fan of base building in RTS games, which is why I never liked Starcraft. Bases in Starcraft feel like they have such little rhyme or reason. They are messy and ugly. I always build a ton of bases in games like Tiberian Sun, that, while gameplay wise, are a waste of time and money, feel fun to build and fun to defend and destroy. I think a really cool strategy game idea would be a logistics themed game. One where building more realistic bases all over a map is a strategy so that they can supply and support each other. Maybe you start out with a FOB and you need to expand into guerilla held territory, but you need to build COPs and Logistics centers to keep your troops supplied and protected.
I always hated in Starcraft how clicks per second is a means to measure how effective some one is at the game. I really want to see a game where tactics and unit composition matter, where a platoon of mechanized infantry face off against like a BTR platoon and, using strategy, you pull through. Have each squad with a realistic composition of like a Squad leader, 2 team leaders, a radio man, 2 squad weapons, a crew served weapon, 2 anti tank units, a combat life saver, and 2 rifle men. I think something with that depth, but with a more coherant interface than like Shockforce, and with pausable real time combat would be awesome. Like Arma but an RTS.
What games would you want to see?
A multi-era multi-conflict first person shooter, with campaigns from the 18th century all the way through to the modern era. Singleplayer, and with tons of weapons, vehicles, and factions to choose from.
Basically, a game much too big and ambitious to ever be made.