FFX is, currently, my favourite game in the franchise. I personally feel that is has the best story, worldbuilding, aesthetics, gameplay and music in the entirety of Final Fantasy. It's definitely not without its flaws though.
The characters are all likeable and fairly compelling, but Tidus isn't the most compelling protagonist. He's arguably kind of irritating at times. He gets a lot better as the story goes on, but it's definitely kinda true. Truthfully, the main issue with the character writing is that a lot of the cast lack much of a personal arc even if they're fantastic characters, which is a bit of divergence from previous Final Fantasy titles. FFVI is arguably more about each character's personal struggles with the main plot as something tying them together than the main plot itself, for example. Whereas FFX is the other way around for much of the cast. That's not to say there's no development, much of the cast does grow from their experiences, but the changes aren't grand or tied to stories beyond the main one which is why it can feel a bit lacking here compared to previous games.
The villains are very interesting though. Sin's true nature and how it's tied to the worldbuilding is really cool and well-thought out. Seymour and the maesters of Yevon are interesting as an embodiment of issues like religious/political corruption, indoctrination and propaganda which are major themes in the story of FFX as a whole. The story also explores themes around racism, abandonment, sacrifice, memory, change and dealing with loss and grief. I find all of those fascinating to explore in fiction and the way each theme always ties back into the worldbuilding itself is really clever. I'll curb my thoughts on the game's writing there, otherwise I might write a full essay accidentally lmao.
Visually, the game is a product of its time in a lot of ways for sure. That being said, the design of the characters and world are excellent. Plus, even with the graphical limitations, places like Zanarkand (both versions), Mt. Gagazet and Besaid are still really pretty to look at and most of the major cutscenes (and all of Yuna's summon animations) look good. Although I wish the other summoners didn't just borrow Yuna's animations without her equipment, making them look a little odd sometimes.
The gameplay is really good. The Sphere Grid is one of my favourite levelling systems in a game. It allows for either linear progression, or more flexible character building which is a lot of fun and the remastered version makes this even better with the expert version. The Conditional Turn-Based Battle system (CTB) is also much better than the ATB introduced in FFIV and used all the way through to IX. It still factors in how speed impacts the order of battle but without forcing annoying time constraints on your decisions. It's a little easier than some previous games technically, but the trade off is that the difficulty is more flexible and you never feel like you have to out of your way to do a bunch of stupid mini-games or sidequests to have characters continue to actually be usable or to keep the difficulty reason. The one mandatory Blitzballl game is annoying and the minigames are about as good (bad) as tradition dictates, but you don't need to do them to keep the difficulty down which is nice. Also worth noting that I think X has one of the better game tutorials because of the way it's inplemented into the story itself and because it makes sense that an untrained and inexperienced fighter like Tidus would need instruction.
The music in FF is always amazing, but I think X still stands out. Too Zanarkand, A Fleeting Dream, Suteki da Ne, Otherworld, Hymn of the Fayth, Mt Gagazet's theme - there's just too many incredible pieces of music and even the tracks that stand out less contribute to a lot to the overall atmosphere. Comparatively, the voice acting is rather inconsistent with some VAs doing great work and others not so much. That being said, it was also the first FF game to feature voice acting, so this isn't much of a shock.
So yeah, there's definitely faults there so I can see why not everybody regards it as highly as I do. But there's just so much good there that I couldn't not provide an alternate view.
