Dying Light comes to mind as a zombie game with multiplayer - while being a great single player slasher game, as a must-play for any zombie fan, it also has two multiplayer modes (i can't say their state or how fun they are because i didn't play the multiplayer in that game; not really a multiplayer aficionado), but at least the single player is super fun. oh, you can play co-op in singleplayer as well - which ups the fun 10 fold!