Free, Clean, Fun. Though.. a bit childish.
I've played Flyff on and off for the past few years (since before GPotato took over the US version).
Basically the best part of it so far is at level 20 you get the ability to fly on a broom or a HOVER BOARD. Which is really awesome. Of course there are tons of monsters, none of which are related to any creatures irl.
The community is pretty good, people tend to help you when you need it. Depending on the class you pick, you shouldn't have too much trouble getting along in the game.
It does break down in the first 1-20 levels when your a magical class (either mage or priest) in the sence you have to constantly monitor your MP.