1. Nelson Mandela: Anti-apartheid leader and former president of South Africa, known for his promotion of reconciliation and racial equality, as well as his commitment to social justice and human rights.
2. Mahatma Gandhi: Indian independence leader and advocate for nonviolent civil disobedience, who played a crucial role in India's struggle for independence from British rule and inspired movements for civil rights and social change around the world.
3. Martin Luther King Jr: Civil rights leader and prominent advocate for racial equality and social justice in the United States, known for his leadership of the civil rights movement and his promotion of nonviolent resistance.
4. Mother Teresa: Roman Catholic nun and missionary who founded the Missionaries of Charity and dedicated her life to serving the poorest of the poor in India and around the world, becoming a symbol of compassion and selflessness.
5. Bill Gates: Co-founder of Microsoft and a renowned philanthropist, known for his work in global health, education, and poverty alleviation through the Bill and Melinda Gates Foundation.
6. Albert Einstein: Theoretical physicist who developed the theory of general relativity and made significant contributions to the understanding of the universe, revolutionizing our understanding of space, time, and gravity.
7. Marie Curie: Physicist and chemist who conducted pioneering research on radioactivity, discovered radium and polonium, and became the first woman to win a Nobel Prize and the only person to win Nobel Prizes in two different scientific fields (physics and chemistry).
8. Jane Goodall: Primatologist and anthropologist known for her groundbreaking research on chimpanzees and her dedication to wildlife conservation, pioneering the study of primates in their natural habitats and promoting the protection of endangered species.
These are just a few examples of individuals who have made significant contributions to humanity and whose impact has been felt around the world. While it is impossible to definitively rank or compare the impact of these individuals, their contributions have undoubtedly made the world a better place and left a lasting legacy.