How Must-Read Writers Change

In my teens, I read everything that I could find that had been written by:

Isaac Asimov

James Blish

Robert Heinlein

Clifford Simak

CS Lewis (not just sf)

I think that that was the complete list.

Observations 

(i) I knew of Poul Anderson but he was not yet on the list. 

(ii) I knew of Ray Bradbury but he was not hard sf and was not on the list.

(iii) Larry Niven and SM Stirling were not around yet.

(iv) Heinlein had not gone down the tubes yet.

(v) I caught up with Simak with The Goblin Reservation (1968) and then stopped reading his novels as they were published, also feeling that he had become repetitive and self-parodying.

(vi) Now Poul Anderson is to be not only read but also endlessly reread.

There has been delay in me acquiring a copy of Simak's City. A friend who read contemporary fiction and no sf read at least some parts of City and wondered why I thought that it was any good. Rereading it now, I might agree with him.

The best sf is very good but. (I know that it is grammatically wrong to end a sentence with "...but." instead of with "but..." but occasionally it feels appropriate.)