For me, you could have the greatest gameplay in the world, but without a good story to back it up, I lose interest. The only exception to this is when a game has some form of great multiplayer mode, but even that only holds your interest for so long. There have been plenty of games with great gameplay that just got repetitive and boring by the end, to the point that I either didn't beat them because I got my gameplay fill and didn't care about the story, or forced myself to beat them and didn't even enjoy the last half of the game. Games like RE4, DMC1&3, and more. A story gives me a reason to push on and keeps a game from becoming boring when the otherwise great gameplay isn't able to support a 10-20 hour adventure on it's own.