Well, I would say 'The Cage' is the best Living Dead map.
It has unique hiding places for humans, and "alternative" attack paths for the zombies.
However, it is way too open, the firing lines cover the whole map and it is way to open. With no lag or network glitches the zombies get cut to peices.
It also doesn't encourage teamwork enough, a single person can easily hold "the cage" so long as Zombie forces are slpit across multiple targets.
I think this somes up what is needed.