What Renaissance landmarks or personalities have influenced most dramatically the culture of the West? How so?

The Renaissance was a period where the rediscovery of classical thinking and tradition led to a rebirth (literally, the word Renaissance translates to birthed again in Latin) of the virtues of Western society and its Roman heritage.
Of Renaissance figures, several stand out as being of increasing importance, largely as reactionaries to the opposing schools of thought issuing from the Ottoman Turkish Empire and the Sultanates even further to the east.
Nicolaus Copernicus and Galileo were perhaps the two most important natural scientists. By their boldness in defying official decree of the Papacy and undertaking a fact-based study of how the planets aligned, they were able to advance the natural science of physics and astronomy centuries ahead during their own lifetimes.
DaVinci is the singular genius of the Renaissance, contributing to studies of engineering, artistry, biology, linguistics, physics and numerous other disciplines.
His patron, diMedici was also a revolutionary figure during the time, as the Medici family showed how the contributions of great houses and politics could rival, oppose and uplift the work being done by church-sponsored thought. Medici's contribution was his taste in who he supported, including DaVinci, Botticelli and Michelangelo.
Finally, Petrarch is the progenitor of the Renaissance as an ideal. He motivated the other thinkers of his time to view the world in terms of its people instead of in the terms of its god. By shifting the focus onto the splendor and achievements of the human, his ideas spurred on others to define the workings of the world around them and create new and exciting concepts. Without his humanism, the Renaissance would not have manifested to value the capabilities and wonder of human achievement, and the rebirth would never have happened at all!

There are many iconic landmarks, cultural icons, and important figures that have influenced the subsequent development of Western culture. Some of the most important are as follows.
Copernicus and Galileo: These two thinkers advanced the heliocentric model of the solar system, one that is now universally accepted. They were pioneers of the scientific method and radically changed the way people viewed the nature of the universe and humanity's place within it.
Martin Luther and John Calvin: These pioneers of the Reformation were the founders of Protestantism, transforming the religious landscape of the West, and inspiring the Counter-Reformation which included major reforms to the Roman Catholic Church. Western Christianity still includes both Roman Catholicism and many Protestant denominations.
Chaucer, Shakespeare, and Milton: These three writers transformed the history of English literature, adding many idioms to the English lexicon, creating iconic works which are still read today, and establishing many modern literary genres and techniques.
Sistine Chapel: The stunning ceiling painted by Michelangelo remains among the best known and most influential art works of the Renaissance.
Palladio: Palladio's work, especially buildings in Vicenza, are responsible for a neoclassical revival in architectural style and influenced many buildings throughout the west.