Battlefield 3 looks like a better single player.
I liked MW2's campaign SOOOO much more then Black Ops. I can't even finish Black Ops' campaign. Its just never sucked me in. I also liked the guns a lot better in MW2.
With that said, i know it's time to stop prestiging in Black Ops. I just don't play enough. By the time i get the Gold Camo it'll be time to replace the game. Which one i get though, I have no idea.