I don't have one, not yet at least. Minimizing online cash transfers is the way to go for me.
Also, as for Modern Warfare 2--out of the question. I'm not a Call of Duty guy, and it's well over 20 bucks.
As for the guys recommending BioShock, unfortunately I've already played and beaten it, but it is an excellent game and I would recommend it to anyone.
I just might look into Killing Floor. Anyone else?