- Good story (a given)
- But don't forget to include fun gaming
Neither one is good by itself in an RPG, you can have much fun with hunts in FFXII, but where's the story?, you can get immersed in Suikoden III's story, but the gameplay makes you cringe, as a result, neither one is as good as they could have been.

- Variety in the character department
Sound like obvious but, honestly: how many more games that are all about a bunch of teens with a token little kid/adult do we need?
Games like FFVI and even Rogue Galaxy are good examples of variety

- Variety in the gameplay
To go from point A to point B with lots of random fights in between, only to go from there to point C to the end of the game with a sprinkle of bosses here and there does not a fun game make.
Again FFVI shines here and so does FFIX, from little things like feeding fish to a dying man to rock a huge cage you are trapped in are things that break the monotony, they don't need to be ground-breaking, as long as they are part of the story.

- Attention to music and design
No one likes forgettable/annoying music and boring/ugly designs, take in consideration that I'm not talking about the latest graphics here, FFXII Revenant Wings graphics don't compare to Crisis Core graphics, but in their own right they are gorgeous, because attention was taken in order to make it look the best possible.
Similarly, in FFXII Revenant Wings, the music was simply taken from FFXII, but it was better placed, more attention to where in the game each track would sound it's best was taken, thus the music is much better enjoyed.