I bought it .
And i really like the single-player campaign, but in my opinion the best single-player is in COD:4 i loved the gameplay and the story.
But for black ops i can say that it lacks something.... hard to say.
About Assasins Creed, i consider Assasins Creed 2 best game ever made, everything was perfect, i will totally remember this game, i even replayed it 2 times.
I suggest you go for Assasins Creed BrotherHood, its awesome!