Allow me to be the first of 'those guys' and brag about the fact that I've played every main series Final Fantasy instalment.
Thank you. Thank you very much.
Well, except 14.
Anyway, my favourite Final Fantasy game is VIII, which is largely down to nostalgia, but I still love it nonetheless. It was one of the first games I ever played, and was the first story-driven game I'd ever played, so being able to wander about wherever I wanted in an open world and take part in a big-ass story was just mind-blowing to me. I know it's hardly the popular choice, and I know it has a lot of problems, but FF8 is my bbygal and I love it unconditionally. It's been knocked off its old pedestal of being my favourite game of all time by Persona 3 but it'll always have a special place in my heart.
So as for the other games. I kind of like 1, I never got that far into it though. It's weird playing it if you've played the later games first, it really feels more like an old Zelda game than a Final Fantasy game. I found 2 to be extremely meh, the villain is a major redeeming factor, but it's a chore to play through, the encounter rate is WAY too high, and the leveling system... my god. Good idea on paper, mental torture in practice. Again, never got that far into it, but I've been meaning to get back to it for the villain alone. 3 is my least favourite. I've only played the DS remake so I'm probably not in that big a position to judge it, but I found it really, really boring, and from what I've heard there isn't much to look forward to. 4 was where it started to get good for me, again, never finished it, mainly because my disc is scratched to hell and the game is really glitchy because of it, but when I get a new copy of Anthology I'll have to play some more, 4 seemed okay. 5 really surprised me, I absolutely love that one. Once again, never finished it, but I got a lot further into this one. I really like the job system in 5. I need to get back to it soon.
You really don't know what you're missing with 6, it was the first FF that can really be called mindblowing. Overhyped a little maybe, but it's still great. I had a disappointing experience with 7, not because I didn't like it, but because before I played it I'd had it spoiled to no end by the fanboys, I'd seen clips of Advent Children, and I'd had it way too overhyped. I do like 7, but not as much as I should, and I'm really miffed that I'll never have the experience with it that the people who played it early on did. 8 I've already mentioned. Mm-mm. FF8. FF9 I loved to no end when I first played it, but when I replay it and when I look back on it, it feels a bit lacking compared to some of the other games to me. Mainly because half the world is completely empty. FF10 I like, but it's definitely not nearly as good as the earlier games. Which makes sense if you know about its development. 10-2... I played it for about an hour, and I spent nearly every second of it cringing in agony. Yeah... no. Jesus christ.
FF11 I played for a grant total of about five minutes, but it's an MMO, and I usually hate MMOs. It had 12's combat system so I wasn't tempted. 12 was where things started to go really sour for me. I haven't played that far into 12, but I really couldn't care less about anything that was happening, and this was the first one I'd played where they changed the battle system, so I was really disappointed by that too. I really really don't like 12's battle system. And Vaan's voice really bugs me for some reason. 13 I don't hate as much as most people, I was expecting it to be a lot worse than it was going in so I was pleasantly surprised, and I was happy to see them bring something similar to the ATB battle system back. But the more the story went on, the less it made sense. And don't get me started on the characters. My god. For the record, the 20 hours in where people say it starts to get good, that was where it started to get unplayably dull for me. And the grinding... the grinding! JESUS CHRIST THE GRINDING. MAKE IT STOP. Never finished 13 so I haven't played 13-2, and I have no plans to play Lightning Returns.
If we're talking about 15 too, with the direction FF has gone under Square Enix, I'm really not hopeful for it at all. I'll play it and give it a chance, but I won't be expecting much.
And this post is getting way too long so I won't get into the spinoffs, but yeah. Favourite 8, least favourite 3. As much as I hate 12 and 13, at least they had SOME substance. 3 is just a barebones FF game.