For an event to be labeled as "most important" it has to be a watershed event, meaning that things before that event were much different than things after that event. More or less this is what I came up with...
1- 10,000 BCE...Neolithic Revolution
2- 324...Constantine I declares himself a Christian.
3- 1492...Christopher Colmbus "discovers" the New World
4- 18th/19th Centuries...Industrial Revolution
5- August 6 and 9 1945...Nuclear Bombs dopped on Hiroshima and Nagasaki.
1- 10,000 BCE...Neolithic Revolution
2- 324...Constantine I declares himself a Christian.
3- 1492...Christopher Colmbus "discovers" the New World
4- 18th/19th Centuries...Industrial Revolution
5- August 6 and 9 1945...Nuclear Bombs dopped on Hiroshima and Nagasaki.