I agree, but his last name is not spelled "Hoffman", it's Hofmann. Hofmann was not only one of the greatest genius' of the 20th Century, but the 21st as well, because he died in 2008.
yeah he's the man this thread seems to be more devoted to genius in the area of human intellect and enlightenment however, the hands down most important genius in terms of human life, Sir Alexander Fleming
Forbes has a good article about the Edison/Tesla controversy: http://www.forbes.com/sites/alexknapp/2012/05/18/nikola-tesla-wasnt-god-and-thomas-edison-wasnt-the-devil/
Edison was a better businessman than a genius. Tesla's AC made the modern city possible. Edison electrocuted an elephant in an attempt to convince people that AC was dangerous compared to DC.
I know about the elephant, Topsy, a circus elephant that had been relocated to Coney Island, Brookyn. It had been mistreated, and killed several trainers. They electrocuted her in Jan., 1903, in Coney Island, a few miles from where I live. There's several sites with a video of the sad event. http://en.wikipedia.org/wiki/Topsy_(elephant)
Going to also have to put forward Norman Borlaug, for his work developing biological technologies and in successfully integrating them into agriculture, allowing for a massive increase in food production and a large increase in food security in many of the world's hungriest nations. Without Borlaug, many great 20th century minds may have simply starved rather than go on to create their astounding innovations, along with other countless millions.
DaVinvi or Einstein They both were ahead of their time and we wouldn't be where we are today in astronomy or physics. E=Mc^2 Quantum theory. DaVinci was one the first to record the human anatomy, built advanced war machines, a machine gun and a tank. You could also make a case for Newton or Tesla but how can you really compare intelligence? People lived in all different times meaning there discoveries are only as significant as their period.