Yes, yes … there are a LOT of “best x science fiction books” out there. I even tried myself, but ended up with a list of my favorites. That’s not the same thing at all … what works for me isn’t necessarily what I think someone else should read, if for no other reason than a couple of my favorites are rather embarrassing.
But this list is particularly interesting: it strikes a good balance between picking books of high “literary” and “genre” value, and between those that are already famous, and those that deserve to be. I was especially excited to see Leigh Brackett and George R. Stewart making the cut, both of which would have been on my list!