As far as FPS games go, Black Ops is above and beyond all others on Wii, without a shadow of doubt! Reflex is next on the list of FPS games but Black Ops online structure blows all others away completely.
In fact, Black Ops has the best Wii online structure bar none. As a Wii online experience it's probably second only to Monster Hunter Tri and MHT only trumps it because of the the gameplay and depth itself, even though it's online structure isn't as good.
And Red Steel 2, whereas it's pretty good, it's still lacklustre if you consider it an FPS.