The obvious answer would be the USA
Well... If you're American!
In addition to the other excellent recommendations, with which I certainly agree, don't forget Canada. We Canadians can offer everything you could want in general aviation, and a float rating too! I venture to suggest, that we have the most open airspace you could ever want. Most of my flying has absolutely zero radio work required, and I'm within 100 miles of Toronto.
Though I do not know the details, I do know that tourist licences are issued by Transport Canada for this type of purpose.
I'd be pleased to make some more detailed recommendations if it would help...
Pilot DAR