The Ancient Greeks were the most important in my opinion. Especially to westerners.
Read up on the classical period. It only lasts a few hundred years and in that time they completely shaped the western mind.
The Greeks did many things. They invented an architectural style thats still used today. Look at the White House for an example.
They permiate the English language with many of our words being combinations or Greek words.
But most importantly they shaped how the western mind thought through their philosophy.







