THAC0 may be gone, but there's a mechanic that replaces it, the attack bonus. Thanks to this mechanic, the issues of attacks constantly missing and some of the low and high level balance issues (at least the ones that don't involve magic) are still present in later editions.

Edit: Why the low rating?

Elantris was his first effort, while Stormlight strikes me as the sum of the best from all his other works, as if everything else is practice for it, selecting some elements of that whole to focus on. What you'll think of the characters depends on the kind of characters you enjoy, of course, but Sanderson shows real understanding of people and of the mind, and in particular how and why people crack and break, coping mechanisms and what may pull one back from the edge or push them over it, and there's a lot about society too, philosophy, religion, ethics, customs, and most of all prejudice. It does strike me as having far too few characters for epic fantasy, but this also allows him to focus more on each. It's mainly a masterpiece of worldbuilding though, but with plenty of action as well, though it understandably takes a while to get going, being such a massive endeavor.
PS: But yes, the main trait common in all his works is how... scientific his magic systems are, and indeed those just scream gaming.

Malazan
The books are rather cringeworthy, but like Forgotten Realms could make a good setting for games.

thx , yeah I like the world and even the motivation or working of the characters , i just dont like the main so far hero and heroine they are just way too good at everything

Mila Jovovich's "UltraViolet" might be fun!

Equilibrium first!

You mean her:

https://en.wikipedia.org/wiki/Isabelle_Collin_Dufresne

Perhaps the Silmarillion since I think it would work a little better as a game than as a movie. The main issue would be deciding what to leave on the cutting room floor and what would really work well for a game. The opening acts probably would work better as highly stylized cutscenes and then the presentation method can become more conventional as the stories resemble modern fantasy stories more. As much as he is my second favorite character, Feanor's portion would not be an easy translation to a more cinematic game (ala Uncharted or God of War). That said, given the strategic terms used perhaps that part of the story can be a strategy game and parts where the story shifts to characters like Hurin and Turin it can be more action oriented in a similar vein as Actraiser.

There are a few Icelandic Sagas that can be really imaginative or just plain cool. Gisli's Saga (these are what they're called given the translations I own, sorry for any confusion) I think can work as a Red Dead Redemption in the Middle Ages sort of game.

A more generic game that's just generally like a saga would make for an interesting Harvest Moon style game. So, you go through the trouble of being a cute little farmer doing your cute little business, getting married and working your farm when one day your brother's killed or your wife's family get swindled in a bad deal and, like all of these stories, you have to go and kill someone. That might get you outlawed, making it very hard to work your cute little farm but if you don't your kids will go hungry. Food for thought.

Bosi and Herraud would be great as a sort of parody RPG like the lighthearted sections of the Witcher 3.

There are plenty of games which use Clash of the Titans as an influence but I'd like to see something more like an action RPG (like Dragon's Dogma) somewhere between God of War (being extremely self aware but too grim) and the mood presented in the movie. Titan Quest comes close, very close in fact in mood but not gameplay (even though it is one of my favorites in one of my favorite genres). Also, Titan Quest diverted too much from the Greek mythology setting. Immortals Fenyx Rising was one of my favorite games last year but its intrusive DRM on console combined with being more like Breath of the Wild and more stylized in visuals than I'm envisioning is why it does not already qualify.

Place it in WW2 like Saboteur, have Nazis shoot at you from their zeppelins, and there's an altitude limit for breathing purposes.

I agree with all the titles you mentioned. It's hard to imagine no one has ever tried to make a few bucks packaging them into a video game because there are plenty of greedy, non-creative idiots out there who would try and exploit anything they can make a few bucks on.
But I especially am glad you mentioned The Three Musketeers. That's one of my all-time favorites--the book and the movies with Michael York and Oliver Reed. (It's been done in a more unfortunate way several other times, but not as a game.)

I'd also love to see a game adaptation of The White Mountains, by John Christopher. I read that trilogy when I was a kid and became a sci fi fan for life. I was the same age as the main characters and strongly identified with them in their escape, their trek across Europe, and their joining the fight against the aliens. (Strongly recommended to anyone who has a kiddo age 12 or so.)

Neuromancer. Cyberpunk as a genre has been done quite a bit in video games, but there hasn't been a notable video game adaptation of the granddaddy of the cyberpunk genre. Video games based on any other Gibson works would be nice as well.

And yes, I am aware of the Neuromancer game for DOS. While that game would be nice to have on GOG, I don't consider it to be that notable.

It'd be really hard to make the game worse than the book. ... ...? :)

Yes, not a Tolkien fan. His best writing -- and only story that's readable to me -- was The Hobbit. I plowed through others out of obligation, but, ugh, don't get where the fans are coming from; LotR had moments [mostly the middle of the three], but, overall was just not terribly pleasant and grossly in need of serious editing and abridgment. Especially The Bible But Worse (AKA Silmarillion).

This is where the movies shine most brightly; Tolkien's stories are good, but Peter Jackson (mainly without being rushed) told them better.

Love & Monsters would be a good mash-up of Last of Us level-dressing and Dark Souls bosses.

It would be nice to get a full Babylon 5 game, not only mods/conversions. There was one in development many many years ago but it was canceled.

Transmetropolitan as TPP talky adventure-RPG (Disco Elysium style) alternating with pure action sequences (No More Heroes style).