Graphics are important, but it's less the quality of the graphics (in terms of photo-realism, et al), and more how the whole package fits together.
For example, I still think Wind Waker is one of the more impressive games, graphically speaking, that is yet to come out. The art design, animations and the like all flow together really well, and it ends up still looking good 10 years after the fact.
Compare that to say, COD4, which was great at the time, but doesn't hold up down the road.
My point is that it's less the number of polygons and shaders and fancy doodads that the graphics have, and more the art direction that makes or breaks a game IMO.