I have come to like Sweden for investment as there has been a marked change in government policy away from socialist policies to more market driven policies. Some examples are the abolition of inheritance tax, a school voucher system and partial privatization of state pensions and social security.
But I am more in favour of countries with large amounts of national resources, therefore I would prefer Canadian and Australian $ and Norwegian Krone. Saying that, one thing I prefer than "strong" fiat currencies is gold, which I am still accumulating.