Avalon...they keep getting better and better. Makes it worth queting more and more. Also enjoyed Wisteria, but I think it could have been more developed than it is...Maybe some extra areas and quests can be added to existing worlds, maybe open up some of the doors or buildings to a quest series across all worlds of the spiral...Add a Carmen Sandiego aspect to it...like a guess where the villian ran to next challenge.
I like Mooshu because of the awesome drops. Wizard City because of Crab Alley, it rocks! Dragonspyre because it's fun to explore. Krokotopia because of the cute manders. Marleybone because it's where you learn my Level 68 spell from good 'ol Dr. Katzenstein! Zafaria because i like the Zamunda music.
In order: Dragonspyre, Avalon, Wysteria, Wizard City, Krok, Zafaria, Grizzletusk (GH/WT), Mooshu, Marleybone, Celestia.
I adore Dragonspyre, and everything about it... even the baddies, especially Yeva Spiderkeeper and Malistaire (dear KI, please give him a sequel~ kthanksbye).
By contrast, words cannot describe how much I hate Celestia. I have 2 wizards there~ Sestiva (storm/49) has taken a detour and is hitting up Ravenscar, while Val (death/65) is purposely avoiding Trial of the Spheres and another Waterworks run.