Uncharted. Great game, and offers something a bit different (compared to R2 at least). It's also cheaper, which should be a factor, since you can use the extra money for another game.
R2 is a bit boring, sort of a standard FPS, nothing too special IMO. Get it if you're really into FPS, otherwise wait till it gets cheaper.
edit: Post above reminds me, if Killzone 2 is as good as people claim, you won't need R2. Also, as one said earlier, CoD4 is a better FPS anyway.







