Zilart/Promathia > Wings > Aht
Zilart and Promathia should be grouped together as the events of CoP happen the second the adventurer resolves the conflict present in Zilart. Bahamut pops outta the sea and the Al'taieu crystal is allowed to briefly communicate with the rest only because Elde'narche messed with the line after his defeat.
Promathia got as close to an offline FF as possible within the constraints of the online environment. Most of the cast were fleshed out, had relevance to the storyline and were likable. You had spunky Prishe, her quiet buddy Ulmia, the voice of reason in Tenzen, the noble savage Jabbos, the rogue Louverance, former enemies turn allies in the Shikaree and 'big sister' Esha'ntarl.
You had a typical 'save the world' story, battles were tough, the zones were creative from the alien feel of Promyvion, the floating regions of Riverne right down to the ancient ruins of Pso'xja, the Lunarian feel of Lumoria and the fight with Promathia above the planet Vana'diel.
SE seems to agree as Prishe got to represent FFXI in Dissidia.