As far as fast freeway driving is concerned, I would place Italy as number one, followed by France, Switzerland, Belgium, Germany, and the Netherlands. In Italy, like in France to a lesser extent, most drivers use the left lane exclusively for passing. You can forget about the myth of no speed limits in Germany.
Freeways are often too congested for fast driving.
Unless you happen to be driving one of the prestigious German makes you will find a very tough time getting drivers in the left lane to move to the right. Drive one of the status makes, i.e. Mercedes, BMW, Porsche, Alfa Romeo, etc. Photo radar is practically useless against speeders with foreign plates. If you want to know where the cameras are, ask any taxi driver. In Belgium there is more speed enforcement than the Netherlands.