In concert with the MM Action poll, I was going to say
Labor of Love, but forgot Dreamfire wrote that. Still think it’s a great story with a clear endpoint built in and a lot of really hot elements.
Speaking of stuff Daphne has actually written,
Above That Ye Are Able.
Trigger Warning and
The Inheritance have a similar basic premise, but what I like about ATYAA is the way he reverse engineers the enslavement process to start making his own new slaves, rather than just collecting the works of another. The darker, vaguely somber tone was also an enjoyable change of pace.
P.S.
Here Be Dragons would make for a fun one-off.