I don't think anyone will, or should, give away their profitable micro niche, as that involves a lot of work to research and find a gem among all the saturated niches out there.
For me, I started with small adult niches that became very profitable due to an engaged user base that craved more content in an underutilized sub-niche. Even when branching out over the years I still kept the sites with that small, but dedicated, targeted traffic base.