While the quests and storyline I found uninteresting, the game does have one of the most unique trading systems. Buying/farming/fishing goods from one area of the game and transporting them to another for profit while worrying about decay is something no other MMO I've seen does.
An example is say, fishing. You catch a bunch of fish off the coast. These fish are specific to that area and are not plentiful in a mountainous area further inland. If you sell them right at the nearest location by the shore you get some money for them, but not very much as the goods are commonplace there. Transport them to the mountains and sell them there and you get a significantly higher price. But you also have to take into account how long it will take you to transport the goods there and how fresh they'll be by the time they get there as decay will cause the sale price to drop as well.
If trading is your thing, you can make a full game out of being a merchant in this, moving goods from one section of the world to another. Buying horses and wagons to help move more goods faster.
Outside of that, the combat is actually fairly involved with a lot of combos to memorize for each class. Though on the surface it looks like you can just repeatedly spam a basic attack, to face higher level creatures you need to start paying attention to which specific moves and combos you're using to deal more damage and which individual abilities you've chosen to train.
PvP is a pretty big deal in the game, but I can't say I've ever tried it. Hate PvP in MMO's in general.
As already mentioned, the character creator is literally the gold standard by which all current games should measure themselves by. The sheer amount of detail and adjustments you can make can literally eat up hours of your time if you're that interested in creating a specific appearance.