Who would you want to meet over a beer? (Turing, Jobs, Knuth, Koch, Elmo, ...?)
This is a difficult question with the recent passing of Steve Jobs, but if he had still been alive I would have chosen him. Being a recent college graduate, I am familiar with Steve Jobs' commencement speech given at Stanford University in 2005. It is one of the most motivating speeches I have witnessed. In his speech Jobs said "Your time is limited, so don't waste it living someone else's life. Don't be trapped by dogma — which is living with the results of other people's thinking. Don't let the noise of others' opinions drown out your own inner voice. And most important, have the courage to follow your heart and intuition. They somehow already know what you truly want to become. Everything else is secondary." Jobs' ability as a technology visionary and creative leader is something this world will miss greatly. Even when confronted about how a certain product such as the iPad wouldn't have a common use, Jobs still went ahead and now the iPad is the #1 tablet in the world.