I don't think I could ever subscribe to "consoles are best" because of games like Dwarf Fortress. Likewise, I don't think I could ever subscribe to "PC games are best" because of games like the Uncharted series. In the end, it's the games, not the platform, that are either good or bad.

But yeah, as for why the PC is awesome: Dwarf Fortress. Also, the sheer number of keys you have access to on a keyboard and the sheer amount of control you have with a mouse. Sure, you can plug them into a lot of consoles these days, but I'm considering the general knowledge of console games being built around controllers first and foremost and PC games being built around keyboard & mouse first and foremost. I just like how much control I have with those things for specific kinds of games, particularly any game that involves a lot of management - so, games like X-COM where you manage multiple soldiers, games like Civilization IV where you manage a lot of everything, games like Dwarf Fortress where you attempt to sort of manage a thriving community of dwarves only to see your management fall apart in spectactularly glorious fashion. Also, Football Manager games.