One of my favorites games of all time. I played FFIV, FFVI, FFVII, FFVIII, FFX, FFXII, and FFXIII.
Of those I liked FFVIII and FFX the most. Although I am glad people did enjoy FFXIII, I really hated that game. I usually enjoy almost any type of game and any genre of game, as a contrast to my roommate who hates JRPGs and many others. But FFXIII really took the cake. Most arguments against it have already been said so I will not bother saying mine.
Back to FFX. I liked the characters a lot especially Auron and Kimahri. The world map was big enough, possibly bigger then my favorite FFVIII. The leveling system was great, could branch off anywhere you wanted. Blitzball was my 2nd favorite minigame below Triple Triad from FFVIII. I have finished the game like 10 times and I have 1 game that is just dedicated to blitzball lol. Summons were done best in FFX imo. Story was great, had a lot of important themes. The length of the game was good with the sidequests. Can take you 60 hours first playthrough plus sidequests for a lot of time. Obviously I can now beat it very quickly. Battle system was still fun and on the first playthrough can be challenging.
Currently trying to finish FFXII and it is really fun too. Already 30-40 hours into it.