I met John Conway at a conference when I was a graduate student in the late 90s. A bunch of us were at a party one night at a faculty member's house, and Conway was sitting at a coffee table with a pen and paper, and a bunch of checkers. He showed us several different combinatorial games. He was a great guy, a lot of fun, and very approachable.
This hurts, especially after losing Freeman Dyson a month or so ago.