Valve or Bioware. I would say Infinity Ward, but after the staff culling, I don't think their company is going to be producing another good game any time soon.
Valve's track record has been flawless, Bioware's too, but they did release the Sonic RPG, which got pretty mixed reviews.
Valve's track record has been flawless, Bioware's too, but they did release the Sonic RPG, which got pretty mixed reviews.