What I'm fascinated by is how many people have played nearly all FF games but 15 and I noticed some of the people that comment in FF threads, haven't played 15. Just thinking....

You phrased it well. Sure it is a small poll and it isn't a majority that prefer the first FF they played (and a lot played many).

But we can say that it seem like there is a great correlation between your first played FF being your favorite or at least among them. Sure we could filter it to verify the discrepancies between people that started on the very beginning, around PS1-PS2 or currently.

One thing I can say is that I really disliked FF XII when I played it, but Zodiac I liked the game a lot. I probably didn't understand 12 enough at the time and it became a problem to play it on the control only the protagonist.

Myself I preffer 13 to 15.

1) FF VI was my first game in the franchise, and also...

2) FF VI was/is my favorite to date. (It's the theme. Has always spoken to me.)

3) I've played all the numbered Final Fantasy games (including the original) with the exceptions of FF XI, FF XII, and FF XIV. I prefer my Final Fantasies more story-based.

Absolutely know what you mean about the theme being a part of your love of the game, some of the FF music is just amazing at invoking emotion, I get the same with Aeris's theme from 7, I can't hear the haunting melody without it being forever associated with THE scene of her, and it pulls me right back to 97 before I would have the internet to spoil it for me so I just sat there in shock after with just that theme stuck in my head of her.

Like I said, haunting theme after playing that game as a teen in my formative years.

1. Final Fantasy VIII
2. Final Fantasy X
3. VI, VIII, X, X-2, XIII, XV, and a bit of VII, IV (maybe), and XIV: A Realm Reborn

That said, VIII too has a strong place in my heart. I doubt I could ever consider it my favourite game of the series, but once I've played even the rest, I expect VIII to hold up pretty well. Also, VI could possibly be my favourite, but I haven't completed it yet, so not quite yet at least.

1 - IV
2 - VI
3 - I, II, III, IV, V, VI, VII, VIII, X, X/2, XI, XII, XIII (all), XV, Tactics PS1, Tactics GBA, Record Keeper, Brave Exvius

1. First: IV
2. Best: IV, VII, Tactics (in no particular order)
3. Played: III (a bit), IV, V (a bit), VI, VII, VIII, IX, X (a bit), XII (many hours), XIII (many hours), Tactics, Tactics Advance

1) Final Fantasy I (NES)
2) Final Fantasy IX (PS1)
3) All main ones and sequels of main ones (except FF11,14), Crisis Core FF, World of FF, Dirge of Cerberus

1)FF X

2)FF X

3) Every single one.

You may have noticed that I have a particular fondness for fiction villains. It's because there's a level on which I feel like I relate, mostly because villains are hated by regular society and, while they may have their moments of glory, you know they're probably going to lose ultimately. That's just how I feel. It's been that way since I was 10. Kefka is a character who was abused and it turns him into a horrible psychopath.

The essential message you get from FF VI is that life is about connections. Love, friends, allies, whatever, but connections. Kefka is held up as an illustration of how monstrous one can become without those connections, once you reach a point of no return and reject them on principle. Not feeling loved by others, and worse, not wanting to feel loved by others, can turn you into a monster. I was kind of at that place mentally-emotionally at that age, when I got FF VI. I needed to be reminded that I was going off an emotional cliff where I just wanted to spend the rest of my life alone.