I'll be honest...did not like FFX. I just hated Tidus, and so the entire story being focused around his daddy issues didn't do it for me. I think that's the same reason VII isn't my favorite. Cloud is just such an unlikable character. He does nothing but whine and complain the entire game. There's not necessarily anything wrong with a protagonist who is a dick, but they at least have to be cool if you're going that route. Cloud looks like a fifteen year old emo kid and acts roughly the same. There's nothing cool about him. And one of your main sidekicks seems like he's in a competition with Cloud to see who can be more of an asshole.
IX, on the other hand, had quite a few really enjoyable characters, from the lead Zidane down to Vivi, one of my favorite characters in the entire franchise. Steiner was really the only asshole in your party, as far as I can recall, and his role for much of the game was essentially as a comedic foil for the more important characters.
I will say that there was nothing wrong with the gameplay in X. I wish the FFVII remake had turn-based combat like that.