This can depend a bit; for a lot of body and low brightness (acidity), you might like Brazilian coffee, or Indonesians like Sumatra. But we find that some of the best coffees that roast dark happen to be the best at any level, coffees with brightness that lingers through into the darker levels, and help keep a darker roast from tasting flat and ashy. Dense, high grown coffee is always better at any roast level. In fact some, like Kenyas, that can be sour in light roasts turn to blackberry / black currant notes at darker levels. Fantastic!