The entry for the PC port bundles X and X-2 together so I'm using this one for it.

This is the first Final Fantasy game that after finishing made me think "damn I want to replay this already", the turn order and rock/paper/scissor combat system is such a natural evolution from the ATB system that makes the game just so much more fun because it gives you control of everything that happens while still facing an adequate challenge.
I also love the sphere grid because it's a cool way to add variety in your builds.
I feel like the only real flaws this game has are the PC ports jankyness, the fact that menus are not able to be scrolled fast and that some areas feel pretty barren, but these are so minor and overwhelmed by the great story and my favorite gameplay in the series that they are null in my eyes.
On a side note the arranged music is amazing, with tracks like "Assault" being an absolute standout.
Amazing game and great entry point if you need a feel for the modern FF games.