I've played Everquest, Ultima Online, Dark age of camelot, planetside, asheron's call 2, earth and beyond, and anarchy online. Of those, I believe Anarchy Online to be the best because it provides a very rich role playing experience that's not your typical "orcs and ogres" atmosphere. You feel like you're really part of a history in the game. Even the little things help the experience greatly. For example, every item or weapon in Anarchy includes a brief description of the weapon, including how it fires and the origin of the design. The information is totally bogus and irrelevant to the game, but it just makes for a better game.