Café Noir in ZH also does quite good beans/roasts:
Also decent is Haenowitz & Page. They are not in ZH - they're in BS - but they do deliver: http://www.haenowitzpage.ch/about/
I really wanted to like the coffee from Schwarzenbach as it's a beautiful shop, but both times I bought some, I felt that the coffee was not quite in its prime. I did wonder if it had been standing there too long? Anyone else had any similar experiences?