I love how the three factions are portrayed completely differently.
I love the writing in the quests and found myself smiling and outright laughing at times. I think the atmosphere and the story telling in this game is the best I have seen.
I found the combat system to be nice, with seven active abilities you don't have to key bind your whole keyboard, and the way you can create your own build of seven active and seven passive from over 500 abilities is really fun. Movement plays a big role, with the ability to dodge out of the way of melee attacks.
I have only tried the two first dungeons of the game, but they were on par with the type of dungeon you find in the "endgame" of other games.
I love how the three different factions are portrayed so completely differently that most players most likely can only play one of them. I found the Illuminati paranoid and far out there, the Templar zealous and righteous, while the Dragons had just the right mix of chaos theory and acting.