CoD 4. I used to play with a community called Skyttegrav (swedish one), and it used to be so awesome. Then MW2 was released, and everyone moved on to that. Playing CoD 4 on random servers just isn't the same. Never the same quality on the admins, never the nice kind of players I had gotten used to. Ended up quitting playing CoD at all, and haven't really played online FPS since then.