Z - PC - 1995 - High-pace RTS based on positioning: http://www.youtube.com/watch?v=mPYRCiskbtE
Z Steel Soldiers - PC - 2001 - Medium-pace RTS based on resource management: http://www.youtube.com/watch?v=hzvnKhZP9A4
C&C Generals - PC - 2003 - Medium-pace RTS based on economic and military eco-systems: http://www.youtube.com/watch?v=Xzz8Eu29TMM
Rome Total War - PC - 2004 - Low-pace TBS/RTS based on diplomatic relations and simulating battles: http://www.youtube.com/watch?v=KgjNRaTgW10
These are the best ones I've ever played. You may find Z very fun and play it casually like chess. Steel Soldiers needs a bit more preperation (if you play in hard mode). Generals is a beautiful combination of arcade and simulation. Total War is pure simulation and each campaign can last for several months.
Prediction made in 14/01/2014 for 31/12/2020: PS4: 100M XOne: 70M WiiU: 25M
Prediction made in 01/04/2016 for 31/12/2020: PS4: 100M XOne: 50M WiiU: 18M
Prediction made in 15/04/2017 for 31/12/2020: PS4: 90M XOne: 40M WiiU: 15M Switch: 20M
Prediction made in 24/03/2018 for 31/12/2020: PS4: 110M XOne: 50M WiiU: 14M Switch: 65M
