Galatea is a text adventure about a conversation with a statue that has come to life. I've never seen NPC interaction this detailed.
It's an old game (2000), but it's new to me... and maybe to you? Free to play.
http://textadventures.co.uk/games/view/emrhyy7pp0c8bjkjeuhs-g/galatea
@ejworthing That's by Emily Short. Have you looked at the rest of her portfolio?
In addition to a ton of adventure games, she worked on programming language stuff with Graham Nelson for Inform and wrote all the docs too -- she worked on a really cool project with the SecondLife developers plus one of the guys from Black and White, called Versu, but they canceled it (after she had already written hundreds of thousands of words, ofc)
She is super cool, very accomplished.
@ejworthing Galatea is great!
I have not played IF in recent years at all, but I recommend exploring the past winners of https://ifcomp.org/ and http://xyzzyawards.org/
My personal favorites in the genre were more long-form story focused: Anchorhead (1998, Lovecraftian horror in the style of Shadow of Innsmouth) and Slouching Towards Bedlam (2003, Steampunk Mystery) and The King of Shreds and Patches (2009, another Lovecraftian horror, set in Shakespearan London).