There will a lot of differing view-points on this subject. Some people are happy buying games with a thread-bare plot, if visuals are above expectations. Whereas others might not mind if the graphics are a bit unsightly, if the gameplay makes up for it with a well thought-out storyline, or perhaps longer game length.
Personally I prefer a compromise of the two. However, graphics have never really been a big selling point for me.
But which do you prefer?
What would it profit a man, if he gained the whole world, but suffered the loss of his own soul?