Nether is a great looking survival horror MMO.  The survival elements are similar to Day Z, except it is set in a vast sprawling decaying city.  The horror elements come from the selection of mutants that roam the cities, hunting primarily by sound and letting out some pretty disturbing screams when they notice you.  The game will also feature some RPG elements and you will also have the option to play on servers with permadeath enabled if you fancy ramping up the tension even more.

UPDATE: Beta No Longer Avaiable