-Definitely the comunity first. If it wasn't for the amazing people here I wouldn't play this game.
-There are still (though not as often as it used to) some epic fights that make me love this game.
-The fact that it's F2P, and when compared to other F2P MMORPG'S, RO is in my opinion the best. I've tried quite a few, and none was worth playing, not after I played RO.
-And last, the fact that RO is still so raw, makes it pretty hardcore.