Proclaiming The Witcher as the new Game of Thrones seems to have become a shorthand to describe it as the current most popular premium fantasy TV show. It's not exactly an accurate description though, while they both involve Dragons and Badassery with a medieval backdrop, the way the two shows are structured and how they focus on their characters couldn't be more different, regardless of the shared genre.
The Witcher's first season seems to be baffling those not paying attention due to its nonlinear time-hopping structure, caused by the inclusion of both short story and novel adaptation going on. It's a unique translation from fantasy novel to TV season that some just shouldn't attempt, so here are some novels that quite likely could (and couldn't) do the same.
Would - The Wold Newton Series By Philip José Farmer
A sci-fi fantasy series that began its life in the 1970s, and kicked off by novels Tarzan Alive: A Definitive Biography of Lord Greystroke and Doc Savage: His Apocalyptic Life, the series hinges on a meteorite crashing to Earth near Yorkshire, England. The meteorite irradiated two passing carriages and the resulting descendants of the occupants were given supernatural powers and a drive for either good or evil.
The novels are all interconnected and use the meteorite as an explanation for most gifted characters in fiction, not only Tarzan and Doc Savage but also Sherlock Holmes, Solomon Kane, The Time Traveler, and even James Bond. A timeline weaving romp would be the way to go and it would definitely make for interesting viewing.
Wouldn't - At The Mountains of Madness By H.P. Lovecraft
Or anything by H.P. Lovecraft for that matter. A writer well known for existential horror, quite often the terror and themes touched on by H.P. Lovecraft are as effective as they are because they are so incomprehensible by and care so little for the existence of the human race.
TV is a very visual medium that allows and encourages deep exploration of characters and settings, something that would likely work to the detriment of Lovecraftian horror. It's most effective in book form in which ideas can worm their way into readers' minds, let it stay that way, or alternatively just use the stories as inspiration.
Would - Skulduggery Pleasant By Derek Landy
The adventures of a thousand-year-old sentient skeleton detective named Skulduggery Pleasant, he chose it himself, as he takes on supernatural mysteries with his assistant, Valkyrie Cain, all with a little Irish flair. It's a bizarre world full of elemental magic, random powers, and necromancy and it would work brilliantly as a TV serial.
Each novel introduces new, fantastical characters and villains, working towards the inevitable return of all-powerful and all-consuming elder gods, The Faceless Ones. The books are full of humor, danger, and some genuinely heartbreaking moments, all ripe for a TV adaptation. Think CSI but with magic and Irish accents.
Wouldn't - House of Leaves By Mark Z. Danielewski
Mark Z. Danielewski's debut novel revolves around a (maybe fake) documentary about a family home that is far larger on the inside than the outside. This just wouldn't work outside of written fiction. Its ergodic literature through and through, meaning it isn't read traditionally or passively.
The book contains footnotes contained within larger footnotes and often alters text size, color, and spacing for effect. Any adaptation would likely come off as a show about a weird house unless some serious alterations took place.
Would - The Final Empire By Brandon Sanderson
The Mistborn Series comes out of a pretty simple idea, what if the Dark Lord of a fantasy series beat the Chosen One. Turns out he would force the world into a cast system, make any descendants of the Chosen One his slaves, and ash would permanently rain from the sky.
An epic on the scale of Lord of the Rings, the books have a mass of material that would work brilliantly. Allomancy, a magic fueled by using different metals, is a brilliant concept that would make for brilliant visuals on screen, and with more rebellions, soaring chase sequences, and intercharacter conflicts to shake a stick at, Mistborn would make some great TV.
Wouldn't - The Silmarillion By J. R. R. Tolkien
Put simply The Silmarillion is more of an encyclopedic collection of myths and tales from the universe of Eä, in which Middle-earth is found, the setting of The Lord of the Rings and The Hobbit. For a time rumors circulated that it would be that basis of an Amazon Prime series, however, the rights simply weren't there.
Perhaps The Silmarillion would work as an anthology series but quite honestly it works far better as supplementary material for ravenous fans. Squeezing a plot out of the many characters and myths taking place in and outside of Middle-earth likely wouldn't do it any justice and would feel too obscure.
Would - The Lies of Locke Lamora By Scott Lynch
The Lies of Locke Lamora is the first book in what is known as the Gentleman Bastard series. Set in a city not dissimilar to medieval Venice, it follows a group of elite thieves known as, you guessed it, The Gentleman Bastards as they rob the wealthy classes in the city of Camorr.
The reader's attention is split chapter to chapter as they see the Gentleman Bastards present-day struggle to prevent the mysterious Grey King from taking over the criminal underworld, and the history of Camorr as it relates to protagonist Locke Lamora. Interweaving timelines and a gritty fantasy setting? Something smells like a Netflix Original waiting to happen.
Wouldn't - The Discworld Series By Terry Pratchet
It's been attempted but never on a scale big enough. For those unfamiliar, the vast majority of Terry Pratchett's work takes place in a world known as Discworld. It's a flat planet balanced on the backs of four elephants which themselves are situated on the back of a giant turtle flying through space.
That's not even as weird as the series gets. Often satirizing tropes of the fantasy genre, most of the book's charm comes from Pratchett's writing style, something that couldn't be replicated across other mediums. The books would just be better.
Would - La Belle Sauvage By Philip Pullman
The first part of an as of yet unfinished trilogy called The Book of Dust, this series is a prequel to Pullman's His Dark Materials series. Set 12 years prior and following the events that led to Lyra Belaqua's arrival in Oxford. The final book in the trilogy has yet to release but the first two books have been well received, so the audience is definitely there for a TV adaptation.
Interestingly, the original series, His Dark Materials, has received both a film and a TV adaptation, both of which failed to impress fans or set up a running franchise. Maybe leading with the prequels and building up to the originals is the way to go?
Wouldn't - Earthsea By Ursula K. La Guin
The books of Earthsea follow Ged, a boy that begins his life as a goatherd on the island of Gont and soon is discovered by a mage and sent to learn the ways of wizardry at The School of Wizards on Roke. While this may sound very Harry Potter, this is just the first book and with 5 of them to adapt the story and incomprehensible magical concepts within would likely be lost or watered down in an adaptation.
Ursula K. La Guin's writing was once described by Neil Gaiman, saying "Her words are written on my soul." With that in mind, it's pretty obvious that the biggest draw to the fantasy epics of Earthsea is in fact La Guin's writing style, meaning the coming adaptation might be lacking something.