Hardcore games are normal ones where only fans of the gene with a lot of patience will play them.(more micromangement for example) Supreme Commander is a very hardcore RTS. While Command and Conquer is not as hardcore as SC it's still not necessary a casual game either. Some games have both casual mode and hardcore modes, for example Forza 3. On easy setting FM3 is as easy as Mario Kart yet turn off all the aids with hard AI you got a more hardcore sim. Even then FM3 is not as hardcore as Rfactor.
The only one of the list that I would consider hardcore is Madden (maybe Doom as well). The others game on the list seems to lean more to the KISS (Keep It Sweet and Simple) approach. That is very simple gameplay yet hard to master.
PS I agree with Killianaia that a lot of today's FPS are seriously dumb down to sell 10 plus million copies.
