I guess what you're looking for is a "Guide Michelin" of coffe shops? For restaurants there are, as you know, guides like Guide Michelin (which only covers Europe though, I believe). I havn't been able to find something like that for coffee shops and bars. I suppose that if it existed it would be even more subjective than the Guide Michelin. Coffee is still just coffee... A way of finding good coffee shops could be to google "coffee shops or cafe + london" for example, if London is the place you're looking for.
Here are some examples of lists:
For Sweden your could have a look at http://www.cafekartan.se/
The new 2013 edition of the Swedish "White guide" also covers "caféer" in different categories. The winner in the categorie "Årets bästa café" was "Olof Viktors bageri och café" i Glemmingebro, Skåne.