Kindle Unlimited is the seedy underbelly of Amazon Kindle offerings, filled with 2nd tier books, scams and trash. But there are also some great books I’d never have read otherwise. And even the books that aren’t perfect can be a fresh perspective over mass market books.
Hard(ish) Sci-Fi / Space Opera
The Privateer Tales by Jamie McFarlane. This series staring three teenagers who foil a pirate attack on their asteroid mining colony and capture a pirate cutter is filled with common sci-fi tropes, but it has the adventure of a Heinlein juvenile with more respect for women and without the heavy handed politics. It’s heroic fiction rather than hard military sci-fi, but the author gives it a plausible military edge at times.
The first book, Rookie Privateer, is actually completely free on Kindle, no subscription needed. The subsequent books are all included in Kindle Unlimited. I’m not sure if this is quite different or edgy enough for @jlw, but it was good enough that I read the whole series.
The Boundary Magic series, starting with Boundary Crossed by Melissa F. Olson.
This is solid urban fantasy staring a tough female lead. Pretty standard pan-supernatural setting with vampires, werewolves, witches and some others. I like the protagonist and the writing and consider the books on par or better than many I’ve read in the genre by popular mass market authors. Olson is a smart writer and it shows.
The Celia Winters series starting with Witch’s Moon by D. L. Harrison.
Witch’s moon is a bit more 2nd tier, lacking the detailed world building, full novel length and copy editing of mass market urban fantasy, yet I enjoyed it a lot. This Harrison’s best series.