In Sweden it isn't the primary language, but virtually everyone speaks it flawlessly, so they have to get an honorable mention.
Not really, this also count for all the other Nordic countries plus Netherlands (which have the same reputation). Don't get me wrong the average Swede are far better at English than the average German, Spaniard, Pole, Frenchman or many other European nationalities, and the people you're most likely to meet as a tourist (in Stockholm) or student do speak the language close to flawless. But leaving the usual international safe space and suddenly will deal with large groups of people who may understand English, but whose skill at speaking the language goes from heavily accented to broken pidgin.
