Jim,
Of the following countries/nations/states (whatever you wish to call them), only Denmark, U.K. & Sweden have had a CONTINUOUS form of government since the birth of the U.S.

Albania, Andorra, Austria, Belarus, Belgium, Bosnia and Hercegovina, Bulgaria, Croatia, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, the Republic of Ireland, Italy, European Kazakhstan, Latvia, Liechtenstein, Lithuania, Luxembourg, Macedonia, Malta, Moldova, Monaco, the Netherlands, Norway, Poland, Portugal, Romania, European Russia, San Marino, Slovakia, Slovenia, Spain, Sweden, Switzerland, European Turkey, Ukraine, the United Kingdom (Great Britain and Northern Ireland), Vatican City, and Yugoslavia.

There are some that MIGHT be considered to have the same form of government such as:

--Vatican City (The sovereignty of Vatican City was officially established in 1929 by the Lateran Treaty between the Papacy and the Italian government.)

--Spain (although during 1873-74 it was officially a republic)

But I can find no others that conclusively have a continuous form of government.

So I guess (If I MUST choose 5 to qualify) I would have to say Denmark, U.K., Sweden, Vatican City & Spain.

--Thom

btw, Thanks for the challenge. I LOVE history.