Love it or hate it, this game is notorious for zealot-faithful players, much rage, and many angered girlfriends. Long story short, it's a modern warfare first person shooter, with a plethora of guns and weapons of all sorts, mostly known for its multiplayer capabilities.
Personally, like Minecraft, I avoided this game like crazy at first. Namely because these sort of games dirty the name of gamers and games everywhere- most of these games don't have anything different from the next, and the biggest difference between them all is the six to ten month delays between their releases. This makes me mad because they're namely made to keep money flowing into their major companies.
Black Ops, specifically, is guilty of being an overly milked cash cow for it's parent company and publisher Activision. The single player campaign has an odd storyline, punctuated by drugged-up interrogations between various missions. Nothing too noteworthy. However the multiplayer is what these games are known for. Also not too noteworthy. Shoot, kill, die, respawn, repeat. For the Xbox 360, this is no problem. For the PS3 and PC, this is a major issue. The game was ported to these severely lagged and glitchy, almost unplayable inherent lag in multiplayer, and was just a disaster. So bad, in fact, a UK group, Gamers' Voice, reported Activision to the UK Office of Fair Trade.
Anyway, in spite of all this, I ended up playing this after my brother got it. This past day has been spent adrenaline rushing over killing countless people in multiplayer. The game itself isn't really phenomenal, but it is insanely fun. As far as I'm concerned, the game isn't worth $60 in the slightest. Luckily, I didn't spend the money on it, though. So I'm perfectly okay with spending time playing it. :D
Long story short, it isn't worth the money, especially considering a new modern warfare first person shooter will be released in a few months without a doubt, and all of the players will swarm to that game. However, if you can get a copy for cheap, or are at a friends house who has it, feel free to play the hell out of it. Theres nothing quite like the rush of a high kill streak. Definitely makes one feel like a badass.