I'd say FFIX, which I think is a great game but in comparison to some of the series crept under the radar to an extent. Especially with it coming after FFVII (the most famous) and FFVIII (possibly the most divisive of the series), and being followed by the first one of the PS2 era in FFX. It has a tendency to be overlooked.

FFV is another one that could fit the bill.

And whoever voted FFVII is a moron, yes XD