The Good: Amazing and gripping single player campaign, stunning visuals and sound, multiplayer is perfect in every way, Wager matches are super addictive, zombie mode is a great treat
The Bad: Some minor issues in single player, only three maps in zombie mode
Military shooters tend to take the most flack because they tend to be the same, linear, some times boring, with questionable multiplayer, but when Modern Warfare came out four years ago it really shook the ground and shooters have been copying it ever since. Black Ops also has something that surprised me, and this was a solid memorable single player experience. Blasphemy right? Wrong! The game has lots of varied environments, tons of epic moments, and a few vehicle sections thrown in, as well as the best helicopter based missions in any game ever. The game also doesn't start out like a regular shooter with Alex Mason (Red Faction: Guerrilla anyone?) strapped in a chair, and a disguised voice yelling at him to remember numbers. The whole story only makes sense at the end and reveals a lot of plot twists and is beautifully crafted and shows developer Treyarch isn't the weak link in the CoD series.
The game has a lot of new weapons that are true to the Cold War/Vietnam era and even the art style shows. The game is beautiful with great sound, voice acting, and and actual plot mentioned above. The game has memorable characters that you get attached to through the 7-8 hours campaign (yes it's also a tad longer than most campaigns in shooters) and even memorable moments themselves. The storming of the Vorkuta prison in Russia, and many other levels are memorable. Of course the game has some issues that Treyarch is known for such as not knowing what to do, poor directions, respawning enemies, and some a few glitches here and there. Despite that the campaign is solid and well worth the wait, and the money, but of course it's multiplayer that most people will keep coming back for.
And oh boy is the multiplayer sweet. With new maps, and a whole new approach to customization, and even the new Wager matches. Black Ops multiplayer is probably the best in the series, and the best FPS multiplayer ever made. The game has the same overall play style of Modern Warfare 2, but instead of recieving fixed unlocks the game adopted a currency system and you can buy everything from perks, to weapons, to visual add-ons, you name it. This is a great approach to changing up the game and making it more about what you want. On top of this the Wager matches are ingenious with players betting before a match and the top three get some money and the rest lose their bet.
There is one in the chamber which gives you one bullet and a knife. If you kill someone you get a bullet, but run out and you left with your knife. This is a great and intense mode because it's not shoot first aim later like the regular modes. Gun Game has you start out with a pea shooter then you move up in tiers of guns with each kill. Not every gun is good because a sniper rifle vs. a machine gun won't be very easy. The next mode is Sticks and Stones which gives you a crossbow, a tomahawk, and a ballistic knife. Hitting a player with a Tomahawk resets their score to zero and the most points are awarded for crossbow kills. Sharpshooter has your weapon switch every 45 seconds and it's random, but every player has the same weapon. These are fun and just amazing modes that never get old.
On top of that is the zombies mode that Treyarch made a cult hit in World at War. You play as Nixon, Kennedy, and two other characters, and along with surviving the three maps, and the hilarious political banter the the characters speak (Nixon when spending points to remove a barrier: This is taxing me like the Democrats). Players, but fight off hordes of zombies in multi tiered maps and points are awarded for barricading windows and shooting the zombies. Points can be spent to buy weapons, ammo, and unlock new parts of the map. It's intense and trying to survive rounds gets heated (most won't survive after round 10, and past round 5 alone). With four players playing cooperatively it's a great departure from the seriousness of the rest of the game.