I love braided narratives, and I'm not seeing a lot of them in the in-box lately. If you don't know what I mean by braided essay, there's a great article/essay on it called "A Braided heart: Shaping the Lyric Essay," by Brenda Miller, in the book Writing Creative Nonfiction put out by the AWP in 2001.
Even if it's written in a more traditional narrative form than braided sections, my dream submission would weave together the writer's experience with history or statistics related to the subject. And if you can teach me something in the process, all the better! It's rare that I can be taught something about childhood by an essay--after all, that's something I've done, something we've all done--so the weirder topics or niche topics tend to fair better.
When I was asked to write this post, I was also asked what I had been seeing a lot of lately. The answer is sex and dead babies. Teenage sex, married sex, masturbation, prostitution, production of porn, rape, child molestation and abuse ... the list goes on. If this is what you're writing about, I'm glad you've come to a point where you can talk (write) about it openly. But unless you're doing something interesting with the narrative form, sex in literature is old hat. There was one essay that crossed my desk about rape and the aftermath, and the only reason it stuck out was that the write had experimented with form in a way that was both engaging and fresh.
Then there's the dead babies. Miscarriages and shaken baby syndrome. I'm seeing a lot of them lately. I'm okay with essays on grief; I'm am publishing an essay on grief this spring--and I cried the first two times I read it--but it's not about a dead baby. As far as essays on grief go, these have the least sense of redemption and a tendency to be written before the author has gained enough distance.