I've had the pleasure to meet Professor Richard Dawkins in Boulder Colorado this year, lil bragging, and had an informative and sincere conversation with him. Nice man! My life changed before I learned of his work so it was nice to "discover" it for myself.
I saw him a few months ago at a literacy festival in Ilkley, West Yorkshire, didn't manage to talk to him personally but he did a fascinating talk would certainly go see him again
One of two books signed and just before our brief conversation.