For me it would have to be the original black ops. That is the last COD game that I enjoyed. My favorite game would have to be WAW, mainly because of the war game mode in that game, that has not been in any of the subsequent games. I think the series has continued to go downhill for sometime now, mainly due to all the assistance that they give players in COD. The death streaks, and things like the target finder in Black Ops 2 are terrible in my opinion. The game seems to have gotten less skill based since COD 4. I also still don't understand how they cannot have dedicated servers with all the money they make, or at least improve the matchmaking. Black Ops 2 is still filled with lag and usually whoever has the better connection will win a firefight. Also after playing my fair share of battlefield, I hate the arcade feel of COD now. Players moving fast, the lack of recoil, I just prefer the realism of battlefield more these days. I skipped MW3, and bought Black Ops2 early this year and after a month I was tired of it. I ended up trading it in for the Last of Us. Unless ghosts really brings some amazing changes I may be done with COD. Right now I don't even plan on playing it at all.