Marvel: Thanks. Like I said, your thread inspired me to actually post this! So, “Thank You, too!” 
detop: I’ll check. I did about half of this from memory. I thought Dangerous Visions was 1970 or 71, but now that I think about it, you may be right. I’ll double check.
Terminus: Maybe Fountains…but I think a good short story collection would actually be better. Clarke’s short stories are so good. Any suggestions?
Amber, and The New Sun are too close to fantasy and I’m trying to stay away from non-standalone books. I thought Ringworld wasn’t as good/important as the other Niven stuff I’ve read, Naked Sun was (IMHO) the least of Asimov’s novels (I’ve always felt it was a mercy-Hugo). But I can be convinced
pink kitten
Got Neuromancer in there already
Steve: The Vance Planet of Adventure is a pretty good idea. It’s kind of forgotten, but Chalker cites it as a source for the Well of Souls stuff, Farmer cites it for the Lavalite World stuff, so it’s pretty influential. And since there’s that omnibus edition, it doesn’t break the “no series” rule! 
You’re right about Stapledon. Which would you recommend?
I agonized about Anderson’s Tao Zero. I may reconsider.
Miller Dammit, this list is too long already. You’re not helping!
Except for The Diamond Age (I’ll consider it, but…I’m not sure) the rest of your list gets onto the master list verbatim. (BTW: If you think I don’t like Vonnegut, you should read what Niven and Pournelle think of him. What they did to him in Inferno!)
Tengu
I’m reconsidering Brave New World.
I’m having an emotional crisis though: I hated Childhood’s End. “Throw the book across the room” hated. I’m trying to convince myself it wasn’t all That important to the genre.
Regarding the Heinlein: I’m more tempted to drop Tunnel in the Sky than Puppet Masters. I like 'em both a lot, but…Puppet is such a good “Cold War” book. I refuse to drop Moon* if for no other reason that it may be my favorite! 
Consider Do Androids added.
I think Lem is a good idea. I’ll put Solaris on tentatively with the caveat that if I get a lot of suggestions for other Lem, I may swap books. Moore’s Utopia-Hmmmm…maybe. The “Alice” books? They’re closer to Fantasy (again, an artifical distinction). On the other hand, you’re right-they’re great. Maybe I’ll do a “Essential Fantasy” list later.
Fenris