Where do you find the best English teachers?

In England! Seriously, the questioner needs to clarify the question. 

There are some countries in Europe where the standard of written and spoken English is of a particularly high standard, Scandinavian countries especially. I would therefore suggest that SOME of the best English teachers would be found in these countries.

I'm not certain I understand your question.
Do you mean this in terms of recruiting, or is this a more general question about which countries tend to have the best Eng teacher? Can you please explain?