Seeing as I'm an RTSer, who have played all on the list to death, I will say that my favorite gotta be Dawn of War 2. Starcraft (both 1 and 2) are brilliant, but macro-management never appealed to me. I prefer the more tactical gameplay from Company of Heroes and Dawn of War 2. That being said, if you're a person who REALLY likes tactical gameplay.. Give R.U.S.E. a try. Good game, overall.
Edit: My reasons are probably because macro-managing is boring in my opinion, I much rather prefer micro-managing. IT TAKEZ SKILLZ DAT KILLZ!