For those who know what FF REALLY means
First off, the characters. This game has 12 characters (and two more secret ones), all of whom have their own backstory and their own distinct personality. Compare that with the recent FFXII, which couldn't manage a real personality for five out of six of their characters. Each of these stories progress as the main game goes on, though for some you have to work for it; Shadow has to sleep in an inn several times, Gau has to go to a certain shop to meet his crazed father, etc. On top of that, each has a gameplay element that makes them distinct. This means that real strategy is involved in who you chose to have in your party. Need Magic Mitigatoin? Bring Celes for her Runic. Animal Skills/Blue Magic? Gau! Gau Go! Like some raw damage and were good at Street Fighter 2? Sabin's your man. Need some heavy Magic damage? Terra's Morph. Etc, etc.
Second, the Story. It's pretty standard fair for RPGs....evil empire, resistance, da da, da da. What makes it stand out, though, is again, the characters. FFVI is a very character driven story; whereas some of the more recent ones make it seem like the characters are "swept up," the players in FFVI make things happen. Cyan's murderous rage when Doma is destroyed, Terra's inability to cope with her heritage, Locke's guilt over the injury to his lady love; all of these character traits somehow play out through the course of the main story. And, of course, you have Kefka. Kefka has got to be one of the greatist badguys that Square has ever come out with. Unlike Sephiroth, who was a great badguy because you could relate to him, Kefka is great because he is simply so clearly insane. From the first time you hear his horrible computer generated cackle, you know you are playing with someone who didnt bring a full deck. Which also makes for some very humorous moments.
Third, the music. No Final Fantasy game (again, with the possible exception of FF Tactics) has had music this good. Nobuo Uematsu was truly on his game when he came up with the musical score for this game; instead of one stand out song (or one of the craptastic "voice" songs we've been suffering through lately), nearly every tune will have you humming along.
There are some problems with this port, though. I would have liked to see some graphical updates, story additions, new items, and such. The extra dungeon is kind of....eh. But for those who love this game like I do, or who love the PSX FFs and never had a chance to try this one, it is well worth the money.