A couple favourites from me.
1) Greece, it has the history, a unique architecture, amazing food and an animated movie set in the country. The only negatives i can see is that there are already a lot of European countries and Greece is bankrupt.
2) Russia, Perhaps the most beatiful architecture in the world can be found in Russian cities, it is a country that everyone knows but very few westerners have seen or been to. If only Anastasia had been made by Disney, plus theres lots of stupidly rich Russians, one of them must be a Disney fan right? The main negative is that politically, you know some imbecile will complain the Disney is un-american or supporting communists.
3) Egypt, it has a history and a look very much ingrained in popular culture and a Pyramid for Egypt opposite the one for Mexico would be amazing. Negatives are Universal already have a Mummy ride and the country is a political powderkeg.