SF Grand Master Challenge - what to read?

I came to this a little late, but the very cool Worlds Without End spec fic book site is running an SF Grand Master reading challenge. It started in January and the idea is to pick and read 12 Grand Master's novels in the year and review at least six. It's an opportunity for me to read some authors I already love and others who, for want of time and/ or motivation, I just haven't gotten around to