World of Warcraft is often the first name that comes to mind when players think of MMO (massively multiplayer online) games. Originally released by Blizzard Entertainment in 2004, WoW has seen more than its fair share of players over the years, with some sources detailing World of Warcraft having over 4 million players daily, and even reaching 12 millions active subscribers in 2010 with the release of World of Warcraft: Cataclysm.