I buy these games for the multiplayer but I do enjoy the campaigns. I thought Black Ops was a ***** campaign, very disappointed. I loved MW 1 & 2, although short was still entertained.
I do like the multiplayer but it has framerate issues on many maps and more frustrating is I cannot connect to any of my buddies when invited or when I invite them. Sometimes I can join their session while they are mid game but thats about it. A patch recently came out which was supposed to have addressed this but it definitely hasn't. I have about 30 PSN buddies that have got Black Ops and not managed to connect to one of them (on invite/invited).
This could be a great MP game but those things need to be sorted ASAP (for PS3 anyway). Love the remote control car killstreak, love the Hacker Pro perk (turn enemy equipment you find into your own) and love all the maps (bar the framerate drops).