Have WarHammer 40k .... it's pretty good. Enjoy it.
Have Ground Control II ... also pretty good. Enjoy it.
But the REAL SLEEPER for RTS is
Kohan II Kings of War
http://www.globalstarsoftware.com/kohan2/The AI seems to learn and responed. Keeps getting tougher. When we started the AI didn't build many forts but now it puts em in and puts em where they do some good. Don't know if it's copying or ............
My son and I enjoy lan games against it.
Note: when setting up the AI portion all players are allowed to input the AI selection. IE I chose 2 or 3 and my son chooses 2 or 3. Also if you ally with an AI it actually tries to help you. Gives you all it's excess funds etc.
Someone put allot of effort into this RTS. If your not very carefull it will kick your ..............