Character progression. I don't mean only PvE progression but also levels, achievements, mounts, titles, beast tribe reputation, currency and logs. It's really fun to hear that level-up sound or see an achievement pop up and know that I've gained something permanent. It's much easier to build a character in this game than in The Other MMO, because you can be any class without having to log off and change characters.

Other things I really like are story and the glamour system. Nothing better than beating a bad guy whilst looking fabulous in the cutscene.