You do not need the original game if you get the disc for the undead nightmare collection. However, if you buy the addon with microsoft poitns you will need Red Dead Redemption. Theyre both great games.
They are both good games. Modern Warfare 2 has an amazing multiplayer but the campaign isnt very great. Black Ops, on the other hand has an OK multiplayer but a better campaign. If you play for social gaming then MW2. If you like campaigns and single player modes then its Black Ops. But overall Modern Warfare 2 is probably a better game.
Someone with a variety of games they play. Someone that works for achievements and has fun at the same time. They get competetive but theyre also fun to talk to. They play for fun, competition, and just to escape reality.