First, I'd like to talk about Rogue Survivor.
Now, there are plenty of Zombie roguelikes out there, but which ones can you really say you had fun with?
I'm not talking standard, roguelike enjoyment. But actual joy. Despite being overly used, zombie games that are truly good are difficult to come across especially with the plethora of cheap zed games flowing out on the net.
RS, is your standard survive the apocalypse setting of a zombie game. It utilizes images instead of ascii art, which are decent and get the job done. The game focuses more on surviving instead of fighting, there's plenty of zombies to go around, you can form groups with NPC survivors, barricade yourself, stock up on items. A cool feature is the games ability to simulate what happens in areas that you aren't present in. The world is constantly evolving.
RS features a simple control setup and ui for those not familiar with roguelikes. You can download it at the Rogue Survivor Website.