I have looked into quite a few free MMORPGs and I believe my favorite so far has been TERA Online.
For those of you who haven't played or looked into TERA at all, here are some things I found interesting about the game.

 To begin with, the character customization was pretty great. There was a lot going on, but not so much that it gets overwhelming.
There are a handful of races to choose from and the classes are categorized by difficulty. However, having chosen the "warrior" class for my character, I can say the most "difficult" class really is not that difficult at all.

 I found the combat to be unique from the other games I've played and looked into.
Rather than just using a hot key to select an enemy and fight them, it is necessary to use a sort of target-dot that remains in the middle of the screen throughout the game. As a result, you can pretty much attack whenever you please without the game telling you that there is no target (not that it actually matters, but I think it's kind of fun). The controls of the game make it kind of weird to play on just a keyboard, so I use a PS3 controller. You can also connect your X-box controller if you have an adapter. The game makes it extremely simple to just connect your controller and play.

 One aspect of the game that I thought was funny was in order to go to certain parts of the map, you must pay a certain amount of money to ride a Pegasus through some crazy tunnel thing and you wind up at your destination.

 As far as the quests go, it is pretty much the same stuff ran over by other RPGs.
"Deliver this," "Kill this many of that," and "Talk to this person." And for whatever reason, I'm alright with this.

 My experience with this game is limited. However, from what I have played of it, I really like how they did most of the game. I think what really got me hooked on this particular game was the unique combat that seems more typical of a console game. Unfortunately, everything on my computer was deleted and I hope to reinstall this game today. I do not play games very often, but I really enjoyed this one.

I'm interested in your experience with MMORPGs! Which is your favorite and why? What makes it unique to you?