I think they really did do a good job of making the graphics amazing, the plot really draw you in with fairly realistic characters, and then fun gameplay that you don't mind spending extra hours just 'playing around' even when it's not purely plot motivated.
You start with the characters being a little rough - the petulant Tidus, the naive Yuna, the close-minded Wakka etc - and they all grow and learn and change over time. You really do start to understand them and relate to them. They each have their strengths and weaknesses, like all humans, and that's fine <img src="/images/graemlins/smile.gif" alt="" />
