For adventures, you could go for some games made by Telltale Games. I didn't play any of those myself, but they're the guys who remain from the Sam 'n' Max 2 project, so they could be good.
For turn-based strategy, I'd recommend Massive Assault, and its expansion.
Not many good console-style RPGs for PC, Anachronox was 'inspired' by Chrono Trigger, it still hasn't much in common with it, due to it using a completely different world. Looks ugly, too. The story and characters are amongst the greatest, though. One of the party members is a miniaturized planet, for example.
Darwinia, for a Cannon Fodder like action game.
Civilization IV, if you liked its predecessors.
I'd say Planescape: Torment for its godly storyline, though it's not console-like, or an action-RPG. But at least it's not an FPS.
Psychonauts is a platformer game, with a wicked universe made by Tim Schafer. If Day of the Tentacle meant anything to you, get this game as fast as possible.
If you enjoyed GTA, you could try Mafia - similar game, but with a better storyline.
For some games similar to Commandos, I'd recommend Desperados or Freedom Force.
...And I believe that's all, excluding games without good graphics, FPS and RTS games.