Some top ones for me would be Brother: aToTS, Blasphemous, Portal, and FF9.
I think all of them would still be best in game form, especially Brother and Portal. A Blasphemous novel would be incredible though. I’d love to read detailed descriptions of the various enemies and bosses. You could also dive into a lot of the tragic miracles in more detail. Its the one I’d most want to read off my list.
Final Fantasy 9 would also work very well as a novel. The game already has a ton of dialogue, and the journey the main characters take would work well as the backbone of the novel. I feel like I can see the outline in my head, and how the story beats could be divided into chapters. A longer novelized version of some of the late Kuja and Garland scenes would make for great emotional drama. The game doesn’t feel rushed necessarily, but the game format does require you to keep it moving, even if it is a Jrpg.
I suppose any of the games with a good plot and not-so-exciting gameplay - I’d probably go for “To The Moon” and the other ones from that series.
It’s the “RPGmaker” one where the two scientists can go into the mind of a dying person, then change the person’s memories so their dreams were fulfilled and they die happy… assuming the scientists get it correct.
If not the full plot, the premise behind it would make a great series of novels or a TV programme.