Personally my favourite is and always has been Final Fantasy IX.
What I always like to ask is when people played their first Final Fantasy game, which one it was, and which one they played next.
For example, I played FFIX, loved it, then played FFVII, it was still a very popular game but this was practically before the internet so it hadn't quite reached the level sof fanboyish nerdom it now holds. In other words, I played FFVII about two years after it was actually released and found it to be fantastic in almost every way. Engaging storyline, interesting characters, gameplay for the time was still pretty unique, and the game felt epic.
A lot of people who criticise FF, especially pre FFX, I find usually played X first, sometime in the early 2000s, so it's no wonder they aren't going to find FFVII quite as good as it was hyped to be. It would be like comparing Metal Gear Solid 2 to MGS1, literally, because FFVII and MGS1 came out in the same year, and MGS2 and FFX came out within a year of each other. And despite the problems with MGS2's storyline, it's hard to deny that there had been significant improvements on the formula.
For another thing, a whole new console had been released between VII and X, along with all the greater limits of what could be achieved, the better understanding of how to tailor games. FFX should have been an upgrade in every single way.
Now, I still hate FFX with a burning passion. It was in fact the game that made me stop playing jRPGs, which had been basically what got me into console gaming in the first place, and I haven't really ever gone back. FFX was so bad it turned me off an entire genre of games, and I've tried others. Mostly when people ask why I just point them at the Spoony Experiment and say 'pretty much that.'
But that's my argument. FFVII hasn't aged well, but then you couldn't expect it to. It was one of the single greatest games ever released for the PlayStation 1, and much as I hate to draw the age card, there will be a lot of gamers decrying FFVII who were barely out of nappies when it was released. Estimating the general age of the Escapist to be around 18-19 means that the majority of people here couldn't have played FFVII around the time it was released, since you would only have been three to five, and maybe it's only nostalgia talking, but remembering the game as the groundbreaking masterpiece it was is important.