i know i hate questions like this in the MW2 section, but i do think this is an interesting subject since there is so many and lots of people like different ones.
Well my favourite is either IX Or X. IX was my first FF so it might not have aged well if i go back to it but X is still one of my all time favourite games so imo X wins.
Favourite characters
Guy Auron
Gal Any of the crazy bitches but it this order Rikku,Vanielle,Yuffie and the other ones