Arma 2: Combined Operations DAYZ mod
is an amazing game/mod which I definitely think you all should look into. I've never had such an adrenaline rush as I get when I play this game.
You are a survivor in a post-apocalyptic world full of zombies. You start out with nothing but a flashlight and some bandage and have to work your way up to a supreme zombie/bandit killing machine. You do this by SEARCHING for weapons and other interesting stuff such as camoflauge suits, nightvision goggles, traps and more. Survival is of the essence and you will do anything to survive - even if it means killing people you thought you could trust, simply because you can't be sure if they are gonna shoot you for your stuff.
It's made very realistic and you have to care for your thirst and hunger as well as temperature and blood (health).
Many weapons can be found, including awesome snipers, full-automatic assault weapons and heavy explosives. Vehicles can be repaired and used such as a bus, car, bike, boat or even a helicopter.
Direct Communication makes it possible for you to beg for mercy or work together with strangers by talking to them with a built in voice chat.
Keep in mind that the mod is in its alpha state meaning there are quite a few bugs but nonetheless it's an amazing game which is bound to make your heart beat fast, make sweat run down your forehead and really introduce you to a truly realistic game-experience. I recommend it.
Here is the official website for the mod where you can read more about it:
A first impression of the game: