I don't know if you guys have heard of that new Arma II mod, but its this crazy realistic zombie mod that came out recently and ever since it did many people are purchasing Arma II. Basically you are a survivor in a MASSIVE world (takes a few hours to walk across), you have to scavenge weapons, food, water, and medicine in towns while either avoiding or killing zombies. You can also make friends or foes with other real players. This game is great because you constantly have to monitor your blood, temperature, thirst, hunger, and sickness.
The anticheat the game uses is called BattleEye and apparently many people have already been banned. Although, I'm sure FPS could come out with an undetected hack, which would be amazing. Let me know what you guys think.