There are some great novel recommendations here, but I wouldn’t say that most of them are lesser-known.
What are your recommendations?
As for me, I’ve exclusively read well-known novels, except if you consider someone like Alfred Bester obscure, for example.
One exception: Misha Burnett’s Endless Summer: Twelve Strange Tales of Mankind’s Future. It’s a collection of exceptionnaly well-crafted stories. It ain’t a novel, though.
Jack Vance has some gems; the Durdane trilogy is a fun time if you ever get the chance. Three short books, “The Anome” (also published as “The Faceless Man”), “The Brave Free Men”, and “The Asutra”.