No tax: UAE, Monaco, Bermuda, etc
I think Nigeria should be on the list too, I don't know about anyone else but I've never for once paid any tax on my crypto earnings, though banks are currently banned from crying out any kind of transactions related to crypto, and are also directed by central bank of Nigeria to block any account that's found carrying out any transaction that's crypto related.
And as for legal tender, we all know that there are only but two countries in the world that have adopted Bitcoin as a legal tender, Nigeria sure is not one of those countries but my prediction is that sooner than later, the government of this country will definitely change their stance on crypto and might likely make it a legal tender.