After playing WoW for 10 years? Playing an MMO that actually feels like an MMO should. The world feels "alive" with people actively out and about doing things in pretty much any given zone, whether leveling an alt/job or just murdering the bejeezus out of some A/S rank that was unlucky enough to spawn.

And what they've done with the graphics is just gorgeous, I never ceased to be amazed by the little things like lighting in certain areas, or little touches like the character actually being wet when wading in water. All without slowing my laptop down.