It's hard to answer this question unambiguously, as each of these countries has its own benefits. Both countries offer visa-free travel to a multitude of destinations. Saint Kitts and Nevis Citizenship by Investment program is a bit more expensive, but it has the largest selection of real estate for investment. At the same time, Antigua and Barbuda fit for those who want to get Citizenship by Investment for large families (6 individuals). Due to the investment in the Fund of the University of the West Indies, the main applicant is able to include his relatives for just $150,000.