To be honest, everyone will have their preferred game, it comes with the taste of each one, for example, (this is totally my personal opinion based on my own experience) people love WoW, I don't like the graphics, and the community is one of the worst communities I have been a part of, went from Retail to Pservers and found the same sort of community everywhere, therefore I stopped playing the game in early 2011.
Right now, I don't have a favorite MMORPG as I have been, actually, playing single player games, yet I played Shaiya for years, and found some servers with a huge and awesome community, which is what I look for when gaming, because we play to have fun, make friends and get away from real world, not to always get insulted and having discussions and arguments with everyone