XII was a great step out of the traditional game play of previous FFs. The world was so vast and of course, there were some more challenges. As for it being better than another, really... There is no such thing as a terrible FF game, but you still have the right to like or dislike it. I didn't care much for XI, and was appalled by X-2. No really. X-2 was an insult for even having Final Fantasy in the title. It was written like a fanfic and Yuna looked sinfully horrible in that gunner outfit except for a few dresspheres. It was a game filled with fan service and the true storyline never came in to play until chapter 3 or 4. (This is just my opinion. I'm not saying this to start an argument or change your views on the game if you like it.) A prequal deserved to be made more than a sequal. Even though people who have played and beat X know what happens to Braska, Jecht, and Auron I still feel like there was alot more going on. :>
I'm looking forward to Dissidia. I just hope they do Kefka's voice good or I will be filled with HATEHATEHATEHATE! xD