Heinlein-“Time Enough For Love”
Ellison-“Paingod And Other Delusions”, “Deathbird Stories”
Asimov-“The End Of Eternity”, “The Gods Themselves”
Theodore Sturgeon - More than Human
George R. Stewart - Earth Abides
Neal Stephenson - Snow Crash
I liked both these books very, very much, but I’m not sure that they qualify as classics yet, which is what the OP wants.
Someone mentioned H. Beam Piper. You have to read the Fuzzy books by him (three in all), and also Fuzzy Nation by John Scalzi, which isn’t a classic yet, but it will be. I found a great deal for a lot of Piper’s books and stories on the Nook, so if you have an ereader, you might want to do a search for a Piper collection. My collection only has Little Fuzzy (the first of the three books) in it, but I have the other two in dead tree editions, I mostly got the collection for the short stories.
The Dispossessed by Ursula Le Guin is one of the great works of literature of the twentieth century, IMO. Better than her still excellent Left Hand of Darkness.
You also appear a little light on old old sci-fi - if you have not read The Time Machine or The War of the Worlds you need to do so. Likewise 20,000 Leagues Under the Sea. Then perhaps some Vonnegut for a change of pace - The Sirens of Titan is a good start.
Also have a read thru the thread about reading Heinlein in his entireity.
Regards,
Shodan
Solaris - Stanislaw Lem - I’d consider this one a “must” for classic sci-fi fans.
Footfall - Niven and Pournelle - I liked that the aliens in this are very “alien”.
The Martian Chronicles - Bradbury
Contact - Sagan - opinions will vary widely on this one. I loved it.
*Timescape *- Benford - not as “action” oriented as a lot of SF, but still an engrossing ‘hard science fiction’ novel.
The Andromeda Strain - Crichton - a lot of his stuff should be skipped, but I’d consider this one a classic story.
Cordwainer Smith - I haven’t read the novel, but his short stories are amazing. You’d think they were written this year.
I wasn’t sure what the threshold for “classic” was, but Fire is older than some of the books the OP listed as classics…
Seconded. Be aware that this is quite dense and challenging. There’s a series of essays entitled The Castle of the Otter that includes a glossary of all of the archaic language that Wolfe uses, but it’s unfortunately out of print.
I’d recommend some Philip K. Dick. Consensus, I believe, is that his short stories are better than his novels (which aren’t particularly long themselves), but I’ve not read any of the short stories, so I can’t say. Specific ones I’ve read and recommend: Flow My Tears, the Policeman Said and A Scanner Darkly. Do Androids Dream of Electric Sheep? is an interesting read to compare/contrast to Blade Runner. (Spoiler: It has almost nothing in common with Blade Runner. :D) I frequently hear The Man in the High Castle recommended, though I’ve not read it myself.
Oh, speaking of short stories, you could do worse than to dip your toe into a little bit of Harlan Ellison. I’ve only read a few of the collections here and there, so maybe someone with more depth will recommend one; I’ll vouch for Angry Candy. The man is, by all accounts, something of a raging asshole, but he knows how to write a good story.
Authors:
Zenna Henderson
L. Sprague De Camp
I have a sort of idea about Crichton, if the movies is good, reading the novel after the fact is underwhelming, I’d apply that to the Jurassic Park novels in particular. If the movie was full of hokey crap, the novel will fill in the blanks that the movie tried to fill in with random action – I really enjoyed reading Congo, and Eaters of the Dead. 'Tho I kinda liked The Thirteenth Warrior, anyway.
Also, I had some fun reading Princess of Mars. I probably would have enjoyed it more if I was 12. But I did like reading what other people read as kids, and knowing now what background they were coming from when they wrote sci-fi.
I really enjoyed Fred Saberhagen’s Berserker series, including novels and short stories, yet they rarely seem to be mentioned in threads like this…
20,000 Leagues Under the Sea is classic sci-fi from way back when. The book is worth reading if you haven’t already.
I agree with others: if these are among your favorites, you definitely need to read more Heinlein: both the “juveniles,” and the earlier, more concise adult novels (like Door Into Summer or Double Star).
I also agree that, if you haven’t read many short stories, you should, and the Hall of Fame is a great place to start.
Thanks all for the recommendations. As soon as I finish my current obsession (The Dresden Files) I’ll dig into them.
Ooh! that one’s on my shelf. My wife loved it. I’ve been meaning to give it a try eventually.
Hey, I’ve got a pretty good smattering! ( if you discount the short fiction and juveniles 
) But you’re right. I was on a Heinlein kick about 10 years ago. I should probably get back to him.
I’ve read a bunch of them, but the problem is they don’t stick for me. I read them, I enjoy them, and then I forget them. Then I pick one up and start reading and everything seems very familiar, like I’ve read it before. Because I usually have. 
Hmm… yeah, I like his work in Wild Cards, but haven’t touched his solo stuff.
Oh yeah, Doomsday Book is one of my all-time favorites, but I didn’t consider her stuff to be old enough to be “classic.” Though I see that Doomsday Book just hit 20 years old! wow! I’m getting old.
Read it. It’s in the OP.
I’m scared. It’s just so massive. It has the whiff of a churned out scifi/fantasy melange. Is it really good? At least to start?
I’ve read the Diamond Age. Snow Crash is on my todo shelf.
Yup, TTM and TWOTW are in the OP. 20,000 Leaugues is a good option, I think. All I know about it comes from League of Extraordinary Gentlemen. I don’t know if I’ve read any Verne at all. Definitely a gap there.
Read it. Liked it.
Hmm… Jurassic Park was so “meh” (after seeing the movie) that I never went back to Chrichton. Maybe I should.
Well, I did put stuff on there that was fairly new, but only if it was a sequel to something older. For the record, I don’t think Shadow of the Hegemon is a classic, for example, but Ender’s Game is, and I wanted to forestall people from listing sequels that I’ve already read. Fire Upon the Deep is borderline, apparently being released the same year as Doomsday Book. I was originally thinking 25-30 years and older, but 20 is probably “a new classic”.
Read it. It’s in the OP. But it was pretty good. I should try some more Dick. er… you know what I mean.
Hrm… yeah, Ellison’s well-known antics turn me off a bit, but I guess I should at least try something from him beyond City on the Edge of Forever (which, yes, I know was butchered according to his account).
Yep. “Fire Upon the Deep” was published the same year as “Doomsday Books” - they tied for Best Novel Hugo.
How about “The Peace War” by Vinge, and “Protector” by Niven.
Abso-fraggin-lutely.
I don’t quite agree that Foundation defines Asimov. I love many of his novels and have repeatedly failed to get through a re-read of Foundation. (It sometimes seems to be all the characters sitting around talking about what did/might/could happen, with almost zero actual, you know, action.)
Try the Caves of Steel/Daneel Olivaw books, at least the first three. Things went downhill for most Asimov when he tried extending and combining his series late in life.
And here I was about to snark at people for recommending Neuromancer. :smack:
So far as Ellison goes, look at it this way: Ellison gets away with acting the way he does because of his writing. That counts as pretty high praise, when you think about it. 
Re Dragonriders of Pern
The first three books (in order published) are great adventures. Dragonflight, Dragonquest and The White Dragon really pull you along (though the latter is a slight dropoff).
The Harper Hall Trilogy (Dragonsong, Dragonsinger, and Dragondrums are also high quality. They’re more a YA version of matters and some of the books take place simultaneously with the first trilogy.
The next book chronologically is Moreta, Dragon Lady of Pern which is good, but the entire story was covered in the previous books.
From then, you take your choice. If you really fell in love with the series, then keep reading. If not, end at Moreta.
It sucks you in. Just read *Dragonflight *and see what you think- you don’t have to commit to the whole series.
But nobody has mentioned Spider Robinson?
He’s not really one of my favorites, but he’s quite popular and well respected.
Well… I can only think of two SR books I’d recommend without knowing the reader and being able to issue a few cautions.
I think most readers who are going to like anything of his will enjoy Mindkiller and the first Callahan’s story collection. Beyond that… eeeyah. There Be Dragons.