I will choose Singapore too. The corporate tax is still reasonable and the country is business friendly. Singapore central bank set clear rules for cypto currencies, so there wont be much surprises coming up like China and Russia.
Yeah, the best bet are countries which already set up clear regulation. Many have none or one in no clear terms, which makes future uncertain. Though EU seems a good choice too, you can hope for reasonable policy. Still, changes in regulations in the future is not a good prospect.