Looking for higher reading level lgbt books

I've been reading a lot of lgbt books lately, mostly m/m, and while I've enjoyed most of them, very few of the ones I've come across have been challenging reads. So I'm hoping to get some recommendations for a more profound and higher level read. The closest I've read to what I'm talking about would be All the World Beside, by Gerrard Conley (very good!)

I greatly prefer fiction to nonfiction, but beyond that I am a fan of most genres. Particularly fantasy/scifi, horror, romance, and historical fiction. But any recommendations would be appreciated!