In terms of impact on world history, Adolf Hitler could be considered the most influential European of the 20th Century. His legacy could be considered great in terms of magnitude, but certainly not great in terms of contribution to humanity.
Traditional African art had had the greatest influence on 20th century sculpture and painting.
James Joyce
Albert Einstein.
internet
Most would consider the greatest inventions of the 20th century to be the automobile, the personal computer, and plastic.
Iris Murdoch
S. Ramanujan
Gore Vidal
Thomas Edison
Man's origins in Africa.
Michael Jordon
John Nash