We talking about your poll options? I mean, best online FPS is very opinionated depending on what kind of gamer you are. "Best" is also very subjective, for me, the closest a FPS game ever got to being the best would be TF2 or Counter-Strike, being balanced and fun (Also subjective) at the same time. COD series is also not that bad (Save for MW2 in my opinion), it's a lot more mainstream but I find it to be really imbalanced in comparison to other FPS games.