While I can't deny that Final Fantasy X had a good story with a well-crafted world, it had its design problems. Dungeons were straightforward with a split to a treasure chest every now and then. It was very linear.
Final Fantasy XIII took X and made it even worse. The first 6 hours or so are a straight line, even dungeons. Come on. I'm told it doesn't really stop there either, and that the game opens up really slow, only really opening up at 20 hours. By that time I could have finished Chrono Trigger with all side quests and had much more fun.