Final Fantasy XI: Chains of Promathia (2004)

Just finished this Expansion for FFXI and this one had the best story yet with plenty of cutscenes and story progression. The characters involved were fleshed out much more than before and the final boss fight with Promathia was awesomely epic. CoP was so good, it made all the hours I've invested in this MMO completely worth the time and effort. It also gives me a sense of excitement for the expansions yet to come.