If I were to choose multiple choices, I would choose Japan, Singapore, Estonia and South Korea. All these countries can be equally credited as the countries with correct crypto-regulations. But, if I were to pick one, I really prefer Japan's way of regulating upon digital currencies in general.
All their governments happen to know the underlying knowledge about Bitcoin and the Blockchain infrastructure unlike some third world countries like India, whose government outright restricts the usage of any cryptocurrencies without getting to know about them in the first place. Making a decision without any underlying knowledge will lead to poor decisions as mentioned above.