I think that Final Fantasy X is the best because I think it had the best story. Personally I felt that all of the characters had true depth (auron ftw) and that the overall tale had the perfect blend of humor, love, and pure hopelessness.
I like Final Fantasy 1 & 2: Dawn of Souls mainly because it was the first final fantasy game I played--not to mention the longest game I played at that time; I wasted hours playing it--and I didn't have any idea how to play the game. I was young when I first started playing it and I had never played an RPG before, so I just wandered around, killing guys, not really attaining to the quests. I also bought the game super cheap and since it lasted me a good several years, it was one of the best video game purchases I have ever made.
my first one was 8 but i didnt find it as great as the others. my favs are 6, 7, 9, and 10. i cant really say which one i like more though XD. 6 was deep, and even though the main story wasnt that amazing each individual character had his own story which is ok (i love terra). i loved 7 because i got really emotional while playing this game and i do think that our world isnt that different from that world. that game just shows my inner thoughts so well (i love aeris and red13). i loved 9 because it made me feel nostalgic and like a child again. it was simple yet complicated at the same time and it made me happy (i love vivi). and i loved 10 for its beautiful story. that game made me feel as if im part of it and i enjoyed every minute (i love yuna and kimahri)
Any Final Fantasy 7. The original one was cool, but my favorite one is Final Fantasy VII: Crisis Core. I didn't really get far into Final Fantasy VII: Dirge of Cerberus, and didn't really like it.
I loved the story, and the leveling system of Crisis Core.
Intriguing story, wonderful fleshed out characters, a villain you love to hate, a massive world of mysticism and technology melded into a wonderful dystopia.
Than FF7 came out and copied the formula, but watered it down.
Check out the [vs]/fave game thread for more of this type of discussion. You are however welcome to make a discussion thread on Final Fantasy. Locking as duplicate.