Answer
Chile and Brazil have some of the strongest passports in Latin America. The Chilean passport is separately singled out for wider visa-free access to developed and popular destinations.
But the strength of a passport should not be the only criterion for choosing a country. Visa-free travel usually means a short trip, not the right to work, study or live. For any individual, what matters more than the overall ranking is the list of countries they actually travel to and the rules for each of them.
When comparing Chile, Brazil and Uruguay, it is worth considering not only mobility but also the time it takes to obtain citizenship, the type of residency, actual residence, language, family grounds and the ability to pass that status on to children. The document should meet your needs, not just look strong in the table.