I'll have to agree with KentyBK there, balance is the key, too much of one kills the whole game for us gamers.
While the gameplay has to be good, the graphics have to be considerably good as well.
Maybe in 1970's, 1980's and 1990's, it wouldn't matter since the graphics were basic (fewer polygons, 2D, etc) at the times, so gamers thought they were good enough.
But now most gamers want to see improved graphics, but "some developers" go too far with the graphics and then barely pay attention to gameplay (e.g. one button does too many functions).
But if it's the other way, problems still occur (textures with little detail can pose some confusing problems that take away from gameplay).
That's why, as KentyBK said, there should be a balance between these two components of the game.