The Ancillary Justice series. Which I think is the best sci-fi I’ve encountered in years and can’t believe it sat on my radar for so long before I jumped in.
If you like scifi that touches on ethical questions, Iain Banks Culture series is very good in that regard, particularly Player of Games and Use of Weapons. I buddy-reread the last one with an internet friend this year and via our discussions got so much more out of it.