I don't really think this is much of a competition. I mean, the games are all quite different and offer very different kinds of game experiences, so they target different kind of gamers. I don't think there are that many people who are interested in several of those games.
If a rap album and a heavy metal album are released the same week, would the rap fan buy the heavy metal album?
Well, I'll tell ya, BF3 is made FOR the PC, and Apparently Skyrim is not.
If it comes down to playability and better graphics, you can guess were my money will go....(Hint)BF3!
Also, comparing Rap to Heavy Metal is like comparing, Music to Video Games!.....Wait.....I Digress.