Well jokes apart there are different ways to determine if a country is a developed or developing country. The two most significant measures would be economic and social measures.
The most important economic factor is economic growth and stability - growing GDP, unemployment rates, per capita income, inflation, cost of living etc. Most countries cannot achieve excellence in all of it, but a reasonable combination of all provides for a steady economy.
After economic stability one has to see the distribution of wealth, business and tax structure. A large disparity between high and low income groups, small and large business, various tax brackets and tax structures is detrimental to progress.
Derivative of the economy is the infrastructure, good roads, efficient public service and utilities system, education and health care systems and other utilities that support the country.
Most important social factors are the very basic core values like human rights, fair and equal treatment of minorities. Next come social freedoms like freedom of speech, expression, civilian rights etc. Derivate of social factors is social environment, social ethics, families, emotional well being, social networking etc. Since society is more diverse than economy bringing about a balance of social factors can be more challenging and open to more subjective measures.
There will always be other factors like technology, environment etc that rise and can either be classified with economy or society or separate. There are some hybrid factors to depending on the nation.
In my opinion based on economic and social factors I feel Scandinavian nations are most developed and progressive. Even though the United States is often cited as a world power Scandinavians are more economically self sufficient and have a more stable and happy social structure. A lot of the Arabic nations and Japan have a high level of economic stability but have weaker society due to human rights issues or social/emotional well being issues. A lot of Asian countries and Eastern European countries are rapidly developing but progress is hampered by corruption, economic disparity and difficulty smoothing social issues. Latin America is also developing and even though behind some Asian nations their development has been steadier. Africa perhaps has the nations that are worst in respect to economy and society. The USA, I really do not know what to say - it is not that economically or socially progressive as it is made out to be.