Ys VIII is my top 1 game i ever played. Everything about it is stellar - the story is phenomenal, interesting, keeping you on the edge of the seat, yet no obvious and has several plot twists, the female co protagonist Dana is amazing and best female game character i have ever seen, combat satisfying and my god is the OST one of the BEST, im still listening to it years after i played the game
Ys IX was amazing, and had nice mystery element, and side characters were better developed... But man, only true ending of Ys VIII has ever made me shed a tears because video game ending (both the ending itself, and not being able to experience this game first time ever again). I cannot recommend it enough!
EDIT: Also about OST, you know other games final boss OST which are hype as hell? Here its first zone level of OST. And it only keeps getting better
Sad OST makes you somber and almost cry, happy OST makes you smile, Boss fights OST makes your blood rush dramatically, and last ending OST makes you cry... a lot.