There is a reason you hear people say "You're some Einstein, aren't you." instead of "You're some Hawkins aren't you." They are both brilliant men, but most of hawkings work depends on the genius of Einstein's theories and equations. Hawkins' greates work was "hawkings radiation" which wasn't completely done on his own. Basically this says that black holes will eventually disappear due to this *big cheer*. On the other hand, Einstein managed to flatten what we knew, or thought we knew, about physics, and rebuild it in a mindblowing way. His theories reshaped the way we view space, time, velocities, light, gravity, and so much more, and in doing so, reshaped all of physics in a major way. His equations, such as E=mc squared, are used to determine the power of nuclear bombs! This is just a miniscule amount of what this man did for the world of physics. Also, study of Einstein's brain proved he was physically a genius due to his massive amount of neurons present in the brain, exponentially greater than the normal human. So, the answer, hands down is Einstein.