(3) Rene Descartes
The Frenchman is no easy matchup given his resume: Father of modern philosophy. "I think, therefore I am." Inventor of dualism, which proposes a disconnect between mind and matter. Maker of wax-based analogies. Inventor of coordinate geometry. Writer of an ontological proof of God's existence. Busy guy.
(6) The Wright Brothers
It's tough to envision the modern world without airplanes, but without a pair of printers-turned-bicycle-makers-turned-glider-builders, ocean liner travel might still be the only way to get to Europe. Although they never attended college, the Ohio brothers were such determined and keen students of mechanics and aerodynamics that they eventually got us off the ground after hundreds of failed attempts at flight. Plus, with apologies to Orville Redenbacher, both Wright brothers are still the greatest people ever to bear their respective first names.
I think I am cramped, therefore I am in the middle seat of a cross-country flight. Descartes gave us an awful lot, from Cartesian coordinates to the whole cogito ergo sum thing to possibly history's only convincing argument based on wax. The Wright brothers, though, gave us a way to get where we want to go as quickly as possible and effectively made the globe shrink for travelers. Who's the greater genius?
[See the whole bracket here.]