Final Fantasy 4 (FF2 on SNES, people here seem to not know this lol) is when the series really started to shape into what it is today. FF4 really stepped forward with developed characters and world. Now characters were predetermined in their own class based on who they are. The story was a bigger focus and with more dialogue. The gameplay being closer to FF1 refined and without class upgrading. Characters would come in and go in your party changing your battle options. For an early SNES title FF4 is a great RPG that really set the standard for the all time greats to come. It still holds up reasonably well today too.