Central America
Central America and Caribbean region have always been very attractive for citizenship aquisition: there are many legal ways (including fast citizenship aquisition) of applying for citizenship. Authorities of these countries are very favourable to new citizens, as their economy is itself quite poor and there is always a big amount for emigrants.
It is very easy to travel with Central American or Caribbean citizenship and passport: it allows visa-free travel to more than 120 countries, including Canada, USA, UK, Spain, Switzerland, Germany, Belgium, the Netherlands and all other EU member countries, Japan, China and most Asian countries, majority of African countries, Indonesia and others.
Nicaragua and El Salvador citizenship aquisition which has all above benefits and even easy and free naturalization in Spain (for Nicaragua passport holders). There are no taxes for worldwide income and no net wealth taxes in Nicaragua ad El Salvador.