If the gameplay isn't satisfying on some level a game can never be great. The benefit of games over other media is that they can make you feel immersed in a world/like you have an effect on that world and the story, like you're accomplishing something. So while you can have a story or graphics good enough to make mediocre gameplay forgiveable, it still holds the game back considerably.
So for me it should be -
Gameplay
Story/World
Graphics
Music/Sound Design
Just look at the great games that have really stood the test of time- Castlevania 3, Pac-Man, Super Mario Bros, Chrono Trigger. They may or may not have had fantastic worlds and stories you wanted to immerse yourself in, but they all had rewarding and engaging gameplay first and foremost.