Don't know what you consider well written, but I find writing style and characterisation important criteria.
Ladykiller in a Bind - great first-person narrator, the bickering with her twin brother is a high point, the dynamic dialogues underline the aspect of social manipulation
Sanguine Rose - nice take on fantasy psychological thriller and a great example how you can integrate lore into narration without losing the story in an exposition dump, really excellent "antagonist"
Vae Victis Khan - I just really like the writing style in this game, you see it in the dialogues and the narration, many characters get a surprising amount of depth in relatively little screen time
A Summer's End - Hong Kong 1986 - almost a KN, focuses on a small cast but the two main characters get a lot of work for that, don't know why they bothered with the non-canonical straight ending though
Good Girl Gone Bad - less a fan of this than I used to be, but still a solid and ambitious branching VN with an MC that can turn into a completely different person
Defending Lydia Collier - nice murder mystery with a good deal of branching, a strong point is the setting, pretty big cast with characters that are all pretty different
