Well this is just a list of the rts games that i play most and prefer:
1. Command and Conquer 3 (modded with Tiberium Essence)
2. Command and Conquer (N64 edition)
3. Age of Empires (2 & 3, did not care for 1 so much)
4. Starcraft (the new one is the best, but i like them both)
5... **** cant remember what this one was :D
This is just a small list.