I am about a week away from launching genre pages, age pages, and filters for all those things. So on the hard-science-fiction page, you can filter to see books in a variety of fun ways and keep following your curiosity:
Which reminds me of https://fivebooks.com/, where people from a particular field are asked their top five book recommendations for a given theme. The interview format is great, and I've picked up a few recommended books along the way.
Lol, I tried it out and put in one of my favorite books, "Liar's Poker" by Michael Lewis and it suggested me a list of "The best novels to help you understand the rich and dysfunctional."