I would be a registered member of the Constitution Party in every state where there is a branch; and an independent everywhere else in the U.S.
As for other countries...
Australia: Christian Democratic Party
Austria: Freedom Party of Austria or Alliance for the Future of Austria
Canada: Christian Heritage Party of Canada or Western Block Party
Denmark: Danish People's Party
Finland: True Finns
France: Front National or Movement for France
Germany: The Republicans
Greece: Popular Orthodox Rally
Hungary: Jobbik
Ireland: Catholic Democrats (The National Party)
Italy: Forza Nuova
Netherlands: Reformed Political Party
Norway: The Christians
Poland: League of Polish Families, Right Wing of the Republic or National Rebirth of Poland
Portugal: Portugal Pro-Life or National Renovator Party
Russia: LDPR
Serbia: Democratic Party of Serbia or Serbian Radical Party
South Africa: Freedom Front Plus
Spain: Falange Espaņola de las JONS
Sweden: National Democrats
Switzerland: Federal Democratic Union or Swiss Democrats
United Kingdom: British National Party