Disclaimer: thoughts below based on my 4 weeks in italy and paris last year. Some people may have had a different experience.
Hmm, you wont find any good coffee in Paris, i know that much. The vast majority of the cafes there use warm long life milk. I spent a week there last year and only managed to find one cafe that had fresh milk. They just arent into freshness for coffee like we are. Its a different culture. To them (the italians and the french at least), coffee is coffee. They arent interested in the subtle nuances of different origins. Its usually just a house blend.
The third wave has really not reached italy or france yet... so you generally wont be able to get a good milk based coffee, or at least that was my experience having spent 3 weeks in italy. The baristas dont seem to know how to froth milk into microfoam, dont clean the steam wands, and have enough ground coffee in the doser to last the whole day, etc. In terms of foam, they know how to make big bubbles and they seem to think thats what westerners want. Best to stick to a caffe (espresso) for less than half the price of a milk based. You also will struggle to find any cafes that do single origins... and of course they roast dark. Which is why the italians can drink coffee late at night (less caffeine in a dark roast).
Having said that, there is a lot of history in europe and some cafes have been there for hundreds of years, which is pretty cool. I found a few that were fantastic (one in rome even had JBM and a bunch of other interesting single origins) but you have to hunt to find those kinds of places. Some baristas in italy dont even bother tamping... but ive seen that in australia, too. I wonder if Beanhunter app for iPhone has many reviews from europe.
Ive only been to italy and france so someone else might have some ideas on places to visit elsewhere.