Only Complete Ren'Py game I can think of that I've liked, is actually my number 1, I Love Daddy. Its pretty amazing if you play through all 10 endings.
I wouldn't say that Good Girl Gone Bad has %complete but it's got a lot of content... I hear there's a problem with the current release, so wait for the update.
Dating My Daughter is technically complete. Ch 2 is ongoing.
Daughter for Dessert has 5 chapters released, its a good amount of content.
I understand your preference for Ren'Py, as I share it, however there are a few RPGM that I think are worth playing.
Zoe's Temptation - this is complete, and its a really cool story I'm glad I played it.
The Artifact - Complete. Pretty straightforward Incest Harem story, but with a cool plot revolving around the artifact itself. Had fun with it.
Incest Adventure - Complete. mostly just because its made by the same person as The Artifact, it was also fun to play and had an ok story for an incest harem game
Coceter Chronicles - Incomplete. This is my second favorite game. When it's complete it will probably replace I Love Daddy at the top spot. It is probably only just ramping up now into something larger, but the first 3 chapters all told are a great game.