Rift

Rift’s greatest achievement thus far is that it has never tried to change the MMO genre, but aimed at perfecting it. The game rationalizes nearly every element of the MMO genre to create a simpler and satisfying experience without letting go of the depth or quality of the genre. It also provides players with plenty of new experiences, taking advantage of the massively multiplayer aspect of an MMORPG. Rift provides the best public quests in MMOs, with big World Events. The game is definitely among the ones you should check out if you are heavily into MMOs.

Info from: http://www.ibtimes.com/top-8-mmorpgs-2012-what-are-gamers-playing-year-426508