Dukes in Windsor are both a great roaster and socially conscience as well. I have bought numerous bags of coffee from them ranging from light, medium to dark roasts and you really can taste the difference. In a city that has so many roasters, I am a repeat customer because they source directly from the farmers and know exactly where their coffee comes from and how it's been treated. I respect that extra step and will gladly help fund that as a repeat customer.
They also have great treats to go with your coffee. They are very busy, but you can always find a chair during non-peak hours.