Foreign educational systems that teach English well?​​​​​​​​​​​​​​​​

Children from Germany and nordic countries usually have a great standard of English, compared to the rest of Europe

This isn't going to be a huge surprise but I find the best learners are ones who find non academic reasons to learn English as well, kids who just do their classes and pass tests are ok but the people who really shock me with good English are ones who were fans of some English media or really wanted some job in an English speaking country. These kids just practice more.

Dutch. But it's not just the educational system that makes them so good at languages; it's the entire environment within their society. Can you imagine a McDonald's job ad in the USA or UK saying, "Must be tri-lingual?" :-) Normal for Holland.

Germanic speaking countries obviously have advantage teaching another Germanic language, because it is less effort, and most of the learning can be done by watching English-speaking media by kids who care (everyone) in their free time. And Finland.