...You know, we shouldn't even be comparing consoles and PC. They're fundamentally different in several ways that just prevent it. PCs have a more versatile control scheme due to the zillions of button combinations on your keyboard; remember the shock and horror at the thought that Starcraft was rumored to be traveling to, what was it, the N64? That never could have worked. Mice are faster than console joysticks; keyboards have hotkeys. This, I think, is one of the main differences that separate the games:
Consoles have Japanese and a few Western RPGs(though this is also due to most console makers being Japanese and JRPGs being many times movies with some interspersed gameplay), many racing games, platformers (you don't need PC power for platformers, and most of the super-popular are Japanese in origin), your less-complex-than-Oblivion adventures like Zelda, and fighting games (which are far easier and more fun when you can just plunk four people on a couch rather than use the internet to link everyone far from each other).
The PC market seems to be mainly in huge/complex and/or interactive adventure games (Oblivion for the former, your stack of MMO's for the latter), Western RPGs (one factor being because they're more control-scheme complicated than JRPGs and require more versatility in the hardware), strategy games (because you just can't do that well with a controller, and FF Tactics/Disgaea don't count), simulation games, and the ilk of all the above.
Anywho, that's my $.02. I'm sure I left out some genres, but I don't know about all of them -- I'm mainly an RPG or action/adventure player. But the point is, if you go for the PC-style games, you go invest in a good computer and have at. If you're one of the old Zelda/Mario platformer types, you go get a Wii, or you sink in for a PS2/PS3 for all your JRPG needs, and there you have it. These days, the lines are actually pretty well-defined, and when they aren't, usually the game has been released for more than one system (even cross PC/console).