Limited again to the awards for Novels, and again, to those who wrote their body of acknowledged stories at a time when one or the other, and preferably both, awards could be awarded (1955 for sure, 1965 preferably).
Strikes me unusual that David Weber hasn’t even been nominated. Honor may not be deep, but some of the middle books were quite a good read.
No Poul Anderson, though, seems a real travesty.
Anderson has won multiple Hugo’s for short fiction. “No Truce With Kings” stands out in particular for me.
It’s tough since pretty much every SF author who I consider decent has won at least once. Bradbury would be a good pick except a few years ago he got a retroactive Hugo for Fahrenheit 451. I’d have to say China Mieville (I don’t think he’s won, but has been nominated/short listed repeatedly); it’s an odd overlooking especially since fantasy writers seem to be the preference these days.
I don’t track these much. But I’m surprised that only one Hal Clement work – the short story “Common Sense” from 1946 – has won a Hugo. And that Cordwainer Smith hasn’t won at all, apparently.
Has Iain M. Banks ever one either?
The Hugos were not awarded until 1953, skipped 1954, and then restarted for good in 1955. They only had fiction categories for Best Novel and Best Short Fiction until 1966. In 1967 they added a Best Novelette category and in 1968 a Best Novella category, to match the Nebulas, which started in 1965.
This severely limits the number of award slots that were open throughout the whole of the Golden Age of sf and the beginning of the New Wave.
Locus Magazine has an amazing database of all the f&sf awards in the world. It’s broken down in all sorts of useful ways as well.
A quick check shows that Iain M. Banks has won 2 British SF Awards, 2 Italia, and 4 Kurd Laßwitz awards but no Hugos or Nebulas. Both awards tend to have an overwhelming bias toward American writers, both because the overwhelming majority of the voters are American and because for most of the history of the awards it was difficult to read non-American authors in their year of publication. People tended to catch up with them later.
China Miéville is in the same situation. He hasn’t exactly been ignored by the world. 2 Arthur C. Clarke Awards, 4 Locus Awards, 2 British Fantasy Awards, 1 Ignotus, 1 Imaginaire, 3 Kurd Laßwitz.
Clement’s award was a “Retro Hugo.” Because of the lack of early awards, a few Worldcons have created honorary award ballots for works that would have been eligible 50 years earlier, had there been a Hugo then. As honorary, 50-year-after-the-fact awards, they are fairly meaningless, going on later name recognition. And there’s only been three of them (in 1996, 2001, and 2004) so they’re pretty arbitrary as well.
Who hasn’t won one? That’s a good question. I don’t want to dig through all the lists to figure that out. Certainly, many good literary writers never even get nominated and most have no chance of winning, unless they break through to wider public awareness, like Kelly Link. In the same way, writers who pump out millions of words of military sf, like David Weber or David Drake or Eric Flint or S. M. Sterling, are equally unlikely to get a nod.
Most everyone in the middle has had some recognition, however. Occasionally it comes from a late award for not quite the best work, but that’s true of the Oscars as well. It’s a comfy, cozy, ghetto. 
Graham Greene, Saul Bellow, Gunter Grass, Vladimir Nabokov, lots more.
First of all, please note that my question specifically excluded shorter than novel length works.
Second, I also asked people to exclude those who wrote when the awards weren’t being given, preferably restricting to those whose works came after 1965.
It’s also kind of meaningless to mention foreign authors, since you generally can’t win a Nebula award when your story isn’t in English (you can’t even be a SFWA member unless you publish in English, and not surprisingly, the awards tend to restrict to the same language).
So, can we have some meaningful contributions here? Ray Bradbury would be one to consider (I don’t consider the retro awards to have much meaning), but how much of his work in novels came after 1955 (and especially after 1965)?
Oh, come on this one’s easy. John Norman.
All of the authors I listed above published (1) novels (2) in English (3) after 1955 (4) and 1965.
Anyway, Ray Bradbury novels published after 1955 include Dandelion Wine (1957), Something Wicked This Way Comes (1962), The Halloween Tree (1972), Death Is a Lonely Business (1985), A Graveyard for Lunatics (1990), Let’s All Kill Constance (2003), and Farewell Summer (2006). He also first published his novel-length treatments (not screenplays) for the movie It Came From Outer Space (1953) in 2003.
If you restrict it to novels only, then the clear example is Harlan Ellison. He’s won more Hugos and Nebulas than just about anyone other than Connie Willis, but never for a novel.
Norman Spinrad has never won any Hugo or Nebula, despite quite a few nominations.
It has occurred to me that humor is never nominated so Douglas Adams and Terry Pratchett are definitely in the running for the honor of never winning a Hugo. Adams hasn’t even won the dramatic presentation or other form Hugo for the radio show, the television series, or the computer game. Admittedly they were up against Donner’s Superman, Raiders of the Lost Ark (I wouldn’t have put this up for a Hugo but I’m sure fan sentiment swept this in regardless of debates of it validity as a nominee), and Return of the Jedi so it would have been an uphill fight…
Bruce Sterling should have won one by now. Then again, he’s better in the short-story format than the novel, IMO.
[heretic mode on]Or maybe he never won because Douglas Adams is a crap writer.[/heretic mode off]
For novels, I have to go for Harlan. A total asshole, but the God of the Short Story.
Gunter Grass published science fiction/fantasy novels? And, to be frank, my point was that if you are writing in a foreign language, even if it gets translated to English, it isn’t going to be considered because it wasn’t WRITTEN in English.
If you’re gonna be snarky, you ought at least to be snarky to the point. 
Keith Roberts. And, as he died in 2000, he’s never going to win one now. (He was nominated for the Nebula twice).
Technically, you didn’t specify SF/fantasy writers. I was all set to mention Shakespeare, until I saw that you had put in date restrictions.
And if I’m using that database Exapno linked correctly (no offense, but that’s the most user-unfriendly web database I’ve seen), it looks like C. S. Lewis has never won any SF (or fantasy? I’m not clear whether those are included in the index) awards.
As I wrote in the other thread, many mainstream writers have been nominated for a Nebula but none had any real chance to win.
There are three classes of writers who have little to no chance of winning a best Novel Hugo or Nebula.
Mainstream writers who write “slipstream” or f&sf books not marketed as such.
Writers who work in languages other than English. (True even of English writers until recently.)
Short story writers, who tend not to write that big novel that garners attention. The field is disproportionally filled with them.
When you talk about best writer not to have won, you’re really limiting the discussion to core field novel writers. And that takes a lot of the fun out of the discussion. Sterling is a good suggestion, though, because even though he’s better at short fiction and has won two Hugos for them, his novels are quite good as well.
It’s not my database, so why should I care? It works pretty well once you figure out its quirks.
The early years of the Hugo, which is the only time when Lewis would have been eligible, were rigidly devoted to science fiction as opposed to fantasy. There was an International Fantasy Award given out in the 1950s, and even that award was mostly won by sf books, although Tolkien did win in 1957 for “Lord of the Rings,” evidently a group award. Realistically, since the only novels Lewis wrote during the period were the later Narnia books and a retelling of a myth, he wouldn’t have been considered even if fantasy were put on the ballot. No short list was ever released for the early Hugos either, so we don’t even know what books might have been nominated.
None of those Bradbury works are major novels in any way, and several of them are mysteries rather than sf. The ones in the field are fantasies, which put them essentially outside the Hugo boundaries as well.
In a small way, this thread recapitulates the division in the field itself, which has a literary side and a popular side which are forever dueling for recognition and complaining of not getting enough.