Today, 24 of may 2015, John Nash passed away in a traffic accident. His wife also passed away in the same accident....
Apart from his work on Game Theory (which I studied a bit back in university), he also had great implications in cryptography and problem complexity.
Here are a couple of good videos about P vs NP. The first one pretty approachable to everyone. Second one is a class from MIT 6.006 by Eric Demaine.
Here's a great talk by Eric Demain I just stumbled upon. This guy is really impressive, follow him everywhere. A true inspiring guy. He's teaching 'Introduction to Algorithms' and 'Advanced Algorithms and Data Structures'