This game is beyond good, it's incredible. If you get an online server going this game will be the main game that you and your friend play!

Little out of place on this list, but this game is absolutely incredible! It proves that the people at Ubisoft indeed have souls.

Grab your mates and kill baddies all over the UK, great game with many hours of fun.

Free, licensed firearms, realistic, intense, can be scary, zombie game. With more than 8 player co-op, oh yeah.

Spiritual successor to Zombie Panic! This game is amazing, a good halfway between No More Room in Hell and Left 4 Dead.

This is an amazing co-op game that we play very often, a good drop in and out game or a game that you can play for 16 hours at a time.