Eve Online is the only MMO that has been able to keep me interested in playing for more than a few months at a time. It doesn't have any elves or dragons. It's not built around a film franchise or a beloved series of books. It is unique in that the content created by the game developers plays second fiddle to the content created by the players themselves. It has vibrant player corporations (guilds) based around third-party websites like
Something Awful and
Reddit (see also:
Fweddit and
Brave Newbies); which leads to in-game drama aka content creation. It offers high-stakes PvP, in that when you die; your ship explodes and the winning player loots your wreck (corpse) taking whatever valuables survived the explosions. It also allows you to
scam your fellow players; which is fairly unique among games. It
regularly makes
mainstream news for it's
large fleet fights and
huge losses. And, you're allowed to use your money to buy in-game currency if you are so inclined. I should note that your characters do not level and you don't earn XP or experience points for killing stuff in-game. Instead, your characters earn points that apply to in-game skills in real-time whether you are logged in or not. Eve Online, because spaceships.