FF6 (FF3 in the states) is an RPG masterpiece that has withstood the test of time. I still maintain that FF7 is the best of the series, but 6 comes really really close, so I can definitely understand anyone who prefers it.
In a time when magic has all but disappeared, a tyrannical emperor and his megalomaniac advisor rule much of the world. A young girl with rare magical talents and a nasty case of amnesia is hounded by the fascist empire, so she falls in with a group of freedom fighters. A noble yet libidinous king, his martial arts expert brother, an honorable thief, a mysterious ninja, and many other characters soon join her in the fight. This simple plot soon evolves into a deep apocalyptic epic, complete with well-developed heroes and villains.
Combat is fun and strategic (thanks to unique skills and a magic system that lets you customize your characters), the gameworld is large, and the plot is fantastic. What more can an RPG fan want? Yeah, there are some annoying parts involving random encounters, and I still get pissed off when characters that I hate and never use get forced into my party, but those are minor complaints. It's not the best game, the best RPG, or the best FF I've played, but I really can't think of a good reason that any fan of the recent Square RPGs should overlook this one, as its available on Playstation. The main flaw is the graphics, and anybody who says that dated SNES graphics make a game unplayable is a real tool.