Friends Computer.
Cod4 server would go down a treat. I'd certainly play when i get my new computer with my last pay cheque. I own the game now, but due to an old computer giving me old values i no longer have a computer.
CSS, also would be great.
I totally disagree on GTA, for many many reasons. Dont get me wrong i own the game for xbox 360, but the online play is near on terrible. It must be the only game i play on xbox that i dont play on live.
Edit:
I also disagree on Cod 5. Cod5 in my opinion is for either new call of duty players (players that haven't experience cod at all) or for people who liked cod3. Cod4 is a much much superior game, different designers, different developers - a different game with the same name :] However with Cod6 modern warfare 2 in the wings we could see a much improved call of duty series game.