Oh yeah I forgot. I have Dead Island. I had some fun with that one! And I have three Dreamcast systems. One is new in box. I just don't have a keyboard. Typing of the Dead added to my list :) In COD World at War and Black Ops do you have to unlock the zombie modes or are they available at the start? I will also check out zombiemod for CS:S.
well i think there are actually some mods for Dayz that are pretty cool, i think there was a new map and somone made a hunger games mod which is pretty cool
ZombieEscape, ZombieMod, and ZombieRiot. All three are quite fun, and you get to play as a human before you play as a zombie, unless you become a zombie by random chance at the beginning of the round.
Killing floor is epic, probably one of the best co-op zombie games ever made, and I believe it was an indie game, and picked up by a major sponsor, all the more reason why it's so very good.