This game is great for custom zombies. It's even better with a bunch of friends. However I only recommend WAW for the zombies :).

This game was recommended to me by a friend, it's so tactical. Two bullets and you're dead. This is a great coop game and it's very cheap!

This game is amazing, and it's only a couple of quid!! If you don't already have it, buy it. You'll love the vast amount of online gamemodes there are!

This game is amazing. You'll meet so many good (and bad) people from this game! It'll take a while to get to a decent level and you may even get demoted