Favourites: Ramza, Orlandeau, Cecil, Locke, Celes, Kefka, Barret, Zidane, Garnet, Vivi, Beatrix, Lulu, Jecht, Balthier, Ashe, Gabranth, Basch, Sazh.
Shoutouts to Judges Drace and Bergan, if I can remember their monologues by heart they're probably well written, not important enough to the story to make the list though.
Least Favourites: Vincent, Cloud sort of, literally everyone from VIII, Rikku, Tidus, Lightning, Snow, Serah.
Vincent and Cloud seem like they were trying to make characters so stereotypically "badass" that I can't relate whatsoever, Cloud kinda grows on you a little bit but still, amnesia as a plot point is dumb. Same for Lightning, except this one is just plain bland and milked to death. Squall is almost hilariously bad for me personally, plus an incredibly stupid looking costume and silly weapon choice. I don't really dislike the XIII cast but I just find it hard to care about them when I don't understand nor want to understand what goes on with the story.