I define good photographers to be ones who make excellent images that are interesting in many ways, from the original concept, messages conveyed, temporality, spatiality, to good composition, but additionally the work is something that achives the above goal by purposefully executing the skill in manipulating the material.
That is, a good piece coming out on chance basis doesn't count as much. Anyone can do this.
But this is just my definition of good photographer, and ideally, I want to be one some day.
When I form my opinion in my mind, I personally value the original concept and messages conveyed by the images a bit more than other factors. I have more respect for those digicam (or even cellphone) pictures that have good concepts rather than innocuously pleasing photos that can be hung in a corporate conference room (those are usually painting, I know). But this is strictly my opinion.
So, what's your view of good photographers?