Which game will end up with higher Life time total. L4D or Resisitance 2?

[RayRay102]

Endz said:
L4D sells so much on Steam, always on the top seller spot. I'll buy it off here also.

L4D I think can keep up even if Resistance gets bundled but can't track steam sales.

 

 I am talking only about the 360 L4D sales, not counting PC and Steam.