Meh, i can't really be bothered to play CS unless it's with friends since i really have no clue as to whether or not people cheat. As for COD4. it was fun for the first 50 or so hours. After that it just got boring seeing every person using the same weapons and perks ak-47, desert eagle ,bandolier, stopping power, deep impact. Or my personal favourite, 3x frag 'nade spam on crash. World at War was far more interesting i find.
The ironic part of the BF3 and CoD* single player campaigns is they try so hard to make it feel like a Hollywood blockbuster. I have had more jaw dropping action movie moments in random games of BF3 than in any other game.