It was a hard choice between Le Guin and Delany for me (and then I was sad for a while about Russ not being on the list), and I might answer it differently another day, because they do such different things with their work... But Le Guin has my heart and my soul in the end, though Delany has more of my intellect in many ways.

*edited to use my new icon, sorry for the extra email!*