Try Rise of Nations. You build a civilization at the same time as an army. You also advance from the Stone Age up to the Information Age.
SW vs ST is getting so heated up now, that there are people that want to debate the liability of the FILMS lol.
I don't like old style RTS ( eg. Age of Empires, with old weapons and troops ). I like advanced combined arms.
Command and Conquer is a great RTS. Allows the use of combined arms, advanced formation, strategic and tactical goals, unlimited population .etc It is awesome, and is to my style, it gives more player control. I am a high speed combat person.
Starcraft is very competitive, is is very difficult. I like Command and Conquer series ( Red Alert being my favorite ), and Starcraft.
I like Age of Empires, and SW Empire At War. I've seen Starcraft played, it looks pretty cool, but it would take some getting used to. One of my favorites is the Sid Meier's Civilization series. Also try Rise of Nations, most realistic RTS i've ever played.
StarCraft II: Wings of Liberty will be out in ten days :D It have been quite a while, 12 years since StarCraft. I have played it for 5 years. I stopped playing after I picked up C&C Red Alert 3 and Age of Empires ( I stopped playing AOE, simply because it is not as good as C&C ). I heard the new StarCraft will be awesome :D If you enjoy Empires at War, you might enjoy StarCraft. PROTOSS FOR THE WIN!
SW vs ST is getting a bit heated up again :D I am not supporting a side, just debating facts.
Well, now you know.
I am probably conservative.