This game is by far, the best Black Ops in the franchise. Hell, one might even say it was the best COD game ever. It was the first Black Ops game to introduce both present time weapons and even ones from a near future. The multiplayer was awesome, and the zombies mode was, too. Black ops cosmetic system was great, and when Black Ops 2 hit, it was like they made it 3x better. All of the sudden, you ha weapon skins for completing certain challenges, and you could buy DLC skins, which were WAAAYY better than the normal weapon skins. Some notable DLC skins (all but one of which came with zombie DLC's) are Cyborg, Weaponized 115, and Afterlife. Although, the 2 best non-DLC skins were the Gold and Diamond skins which you get get (gold) for doing all skin challenges on a weapon and (diamond) by getting gold for all of the weapons in that category, etc. Shotgun or Sniper.
Zombies. Zombies was the best aspect of this game, in my opinion. I loved Origins, I remember being, 7, maybe (I had older bros who were 9 and 10 years older than me) and I remember waiting for a day or two, just to download this DLC, but in the end, it was worth it. All of the zombies maps were ok, except for Die Rise. We don't talk about that >:(
Black Ops 2 was the best game in COD history.