cAPSLOCK on 06 August 2008
Armed Assault (mission editor=never boring)
Galactic Civilizations II (insane depth, can play for years and still not master it)
After that, I'm not totally sure.
3rd Party Wall of Shame
http://www.nintendoworldreport.com/forums/index.php?topic=30478.msg581036#msg581036