After much experimentation, I have become a ninja assassin in Modern Warfare 2.

     Now the first step in becoming a ninja assassin, or "ninassin" for all you texters out there, is to never use bullets. Anyone who has ever played this game knows how useless they are anyway. Step two is to get a tac knife. Now some people might be saying "but Driving, you can't get a tac knife without using bullets. Does this mean I have to use the crappy default class?" The answer is no. Never use the default class. Each ninja's blade must be unique (within the five guns it's available for). Little known fact, if you depress all buttons and both thumbsticks while holding a handgun, you will throw your handgun. This works like direct impact. 
 
    Once you have your tac knife, set up the following class. Handgun with tac knife, smoke grenades, throwing knife with Marathon, Danger Close and Ninja. Marathon and Ninja are to run silently.  Ninja also makes you invisible to heartbeat sensors because you will have surgically removed your heart.  But the most important perk is Danger Close. When your ninja assassin awesomeness explodes all over your enemies, you'll want it to have a wider blast radius.
 
    The next step is to camp at a high point on a map, like the cliff on Afghan. Snipers rarely look here because they are too busy running around using thirty-plus pound weapons as sub-machine guns. Your back is exposed here, but it doesn't matter. Ninjas hide in plain sight.
 
     In a typical Free-For-All match of eight people anywhere from 2 to 2.5 of these players will not be camping. When these people run below you, leap off the cliff and skewer your wanna-be opposition. Don't worry about the fall damage. Ninjas always land on their feet. 
 
    In team games, it is your job as a ninja assassin to get behind enemy lines and mess people up. Deploy the smoke and attack with throwing knives. DO NOT use your tac knife for team filler. That special blade is reserved for the best player on the team. Kill everyone with the throwing knife before you tac knife him for the Counter-MVP challenge. Rinse and Repeat even without more smoke grenades. Odds are it won't matter anyway. Usually the enemy team is so overwhelmed by the ninja awesomeness that everyone quits out after the first stealth mass assassination.
 
   This is the path is becoming a Ninja Assassin. Walk it carefully.