Oo! Very deep, profound question, and I have seven minutes to answer it before I have to leave, so here goes...

The most important thing in an RPG is Gameplay. Take FF1 for example; the storyline and character devo weren't much to speak of... it was generally run-of-the-mill... but to this day there are those who claim that FF1 is the best RPG EVER, and the excellent gameplay puts a lot of support to that.

The second most important feature is music. Bad music can ruin a game. Again, take FF1, the old NES version. Although fine for it's time, nowadays FF1's music is so godawful, Cthulu himself plugs his sound-receptors in pain. If they hadn't remade it with better music I doubt I'd play it as much as I do now.

The third most important thing is variety. Variety, as they say, is the spice of life. Having lots of neat weapons, characters, sidequests, abilites, magicks, etc., make sure almost any gamer can find their niche in the game.

Fourth is length. Some RPGs are just too bloody short. It can have the best music, gameplay, characters, story, etc... but if it only lasts me a week, I'll be pissed.

Fifth is story and characters. I group these together because they really intertwine. Without the characters, the story would fail and without the story, the characters would just sit there and you wouldn't be playing the game in the first place. A good, creative, interessovating story is highly integral to the overall satisfaction of the game.

Sixth and last is graphics. I don't care if it's 2D, 3D, SD or realistic... just make it look good. I have no problem looking at pretty games like the FF1 remake or FFX... as good as it is, though, FF7 is painful on the eyes.

*breathes* Whoo! Made it with one minute to spare. As a final note I'll add that the battles must keep exciting, as that was the downfall of an otherwise superb RPG, LUNAR: SSSC. Great everything except for the battles, which were repetitive and boring.

Thank you, and have a nice day.