From my experience working in many places all over Europe the last 20 years plus, the key factors for good coffee imho are: - A tidy coffee machine. Coffee gro

From my experience working in many places all over Europe the last 20 years plus, the key factors for good coffee imho are: - A tidy coffee machine. Coffee grounds are home for all kinds of living organisms that can make or break a cup of coffee. This is the killer factor. - The water (hardiness, etc). Madrid has, arguably, one the best tap water in Spain and probably tops most European capitals. Most islands in the Mediterranean have sorry coffee due to the use of treated saltwater as tap water - from tap right into your espresso. Yuck! (obviously not a problem at a 5 star place where they use mineral water). - The milk. For the best experience try the coffee in Galicia, and some parts of the North of Portugal. Some rural towns with a tradition in dairy production can give you a pleasant surprise if you're looking for that creamy taste with a foamy light texture. Rural areas is also where dirty machines dwell, so it's not a guaranteed good experience. - The coffee and coffee culture. Generally most places carry the national/local brands. Italy definitely has the best mass produced coffee brands, but Portugal is a close second for their awesome ristrettos. The rest of cities or neighborhoods... It depends on how upscale they are. Ie. Chamberí is smart and upscale. I'm not comparing coffee shops with baristas, but the average coffee you get in the off-off places where tourists would not walk in but that account for 99% of all coffee served in Europe. But I believe that's the least important factor tbh.