I'm really bias here, but Final Fantasy X is my childhood and Yuna is for me such a well written character. Not everyone would have the gut to every start such a jouney and even less would be able to handle everything seymore does to her. Yes i think Seymore is an perfect antagonist, you just have to hate him. Tidus is fine as well, but i didn't metion him because i have other male mc's that i like more.
And Dana from Ys VIII: Lacrimosa of Dana is one of my favorite chars as well. She just overcomes thing not everyone would be possible... hard not to spoiler and say something.