Of all time: 1) Agriculture 2) Wheel
Modern man: 1) Printing press 2) germ theory of disease/penicillin
20th century: 1) Transistor 2) Integrated circuit
Greatest moment:
Of all time: The resurrection of Jesus Christ (i.e. birth of Christianity)
Modern man: Copernicus/Galileo revolution (Helio-centricity/battle against authority for freedom of inquiry)
20th century: Man walks on the moon