According to Terrence Henry of The Atlantic Food Channel, Buenos Aires leaves much to be desired in terms of food and flavor. He notes that most restaurants use wood-fired grills, which he thinks blanket all foods with similar flavors. He also comments on the lack of variety in the street food available, saying that it is limited to empanadas.
A great food city is a place that caters to all manner of the food-obsessed: vibrant street food, affordable ethnic and traditional dining, and highly acclaimed (and more important, highly respected by their peers) destination restaurants. It should have a connection to its seasons and soil (or sea, as the case may be). It should be a place that can alternately surprise and comfort, at any budget level.
What, to you, makes a city a "great food city"?