If you'd have asked 2 or 3 years ago, I would have said the best game I ever played, but games like Parasite Eve (and especially The 3rd Birthday), Persona (especially Persona 3), FF: Crisis Core, Bioshock and Resident Evil changed that. Some games I listed are even superior than Final Fantasy X.
10
The linearity in X was never a problem for me. It is not as glaringly obvious such as in FFXIII which has next to no sidequests or world outside of the main game.
