In my opinion there are a few things that really differentiate PC from console:
1) Graphics quality: drastically more horespower to render 3d means games will look better on a reasonably powerful pc. However, many people that don't value those differences may not notice the distinction as much as others.
2) Controllers: to me, keyboard + mouse is miles ahead of console controllers in amost all games.
3) Versatility: you can use a computer for a broader set of activities than consoles (though consoles are doing a great job of expanding their multimedia role).
4) Value: consoles provide a really unbeatable value for gamers as compared to PC. $2-300 gets you in the door. End of story. $500 is really the starting point (sans Operating System) for a decent gaming rig. To build something more substantial you can top $1,500 very easily.
5) Ease of use: building and really getting the most out of a gaming PC requires a lot more know how. From updating drivers to troubleshooting, you just don't have the same hassle-free maintenance that consoles have.
Given the above, I very rarely buy a game for consoles that's available for PC. Get yourself a solid rig, understand the tradeoffs, and enjoy those amazing visuals!