The story line which changes from char to char.
The combat animations.
The fact that I can alter the story and my place in it, by just answering a different way.
The worlds are diverse, well laid out and have a feel all their own.
Until now, I gave up on grouping. With gear-score, parser's, mini-generals who tried to dictate your game play, etc it felt more like work and an obligation than game play. Now, grouping is fun again.
I love the combat system.
No elves!
Youth. Yes, this is a brand new game that will get better and better over time and I'm in on the ground floor.