I'm tired of seeing the same recommendations everywhere. What book can you recommend that you think no one else will know about that you enjoyed? Any topic is welcome!
I'll start:
Thinking Fast and Slow - hahaha joking, I got you there ehhh!!!
what about hmm:
Critical Path by Buckminster Fuller ?
Probably 90+% of books published are "obscure" in the sense that they didn't become best sellers and won't be recognized by the average person or likely mentioned in a list like you requested. Most books just don't become popular enough to be well known. Which I think is a tough benchmark.