Ok I need help fellow fluther gamers or FPS heads what game should I choose?

So I got a little extra cash and games to trade..

There is couple games I’m looking at but which one would you get and why?

Call of Duty: Modern Warfare 2

VS

Battlefield: Bad Company 2

Help me out here which one takes the cake in the end eh??....I will probably buy both at one point but just got enough cash to blow for one right now.