Depends if it's a jrpg or a wrpg. The gameplay definitely needs to be good if it's a WRPG just because they're usually dark/glum and contain forgettable characters (generalization). For a JRPG, the gameplay just needs to be decent; but the story is what really shines for a JRPG.

@dsister
I think I would have to go for...........story. Oblivion's battle system is crap, but the fact that the game is so expansive with quests and side stories(kind of the games plot) that I couldn't put the game down.

I gotta go with story...hell I think I could have tolerated 12 if the story and Vaan were good.......

Give me another FFX

Gameplay. They're games afterall O_o
There's plenty of great RPG's with a crappy story (Pokemon, Paper Mario, Kingdom Hearts).

Gameplay. A well designed system like FF7's materia can provide endless hours of fun while a poorly designed one like FF8's junction can make a game intolerable. The story just sorta happens to be there and is wholly inconsequential.

Playstation!! It needs to be on the...

wait.. was that a choice?

Gameplay. A good story is just a nice addition. Then again you are asking the guy who skipped every cutscene in FFX and KH2. I play a game to have fun. If I want a good story I could read a book.

Story, without the motivation to move forward in the game via a good story the entire enterprise breaks down into a series of level grinding and mindless fetch quests.

depends on the genre but usually story/setting/atmosphere they are all part of a whole for me, as long as it's playable that is unless you include things like skill/magic system etc in game-play.

well it's complicated

story i have to say because that's what got me into RPG's in the first place. I hated how FFX played at first but I wanted to follow the story so I kept playing it after a while I loved the gameplay lol