I was at Best Buy today and decided to buy a PC game. I was going to buy BioShock. I was looking it over and it did not look all that great, so I just bought Battlefield 2142.
Don't get me wrong, Bioshock is a "awsome" game and everything.
It looks super and really has a good gameplay, but once you finish the story there isn't much to do.
Battlefield on the other hand is maybe not as good-looking but has nice multiplayer gameplay.
Making it last you a hell lot longer than Bioshock.
Besides, you could just download Bioshock since its fully functional that way aswell, as for Battlefield you need a key inorder to play online.