other than the laughing scene and maybe one or two other parts I think yuna was the only one that consistently bothers me, tidus gets a lot of flack but I don't see him as being half as obnoxious. I think wakka, auron, lulu and jecht are all pretty well written and acted. seymour is kind of a generic and bland villain but other aspects of FFX are strong enough to ignore that, I think it kind of fits within the theme of the game as it is
spira is one of final fantasy's most brilliant worlds, it's really too bad you can't freely traverse it until very late in the game