This Is How You Lose the Time War
Gorgeous writing and a beautiful enemies-to-lovers storyline that is both mischievous and aching.
Gideon the Ninth
You can summarize The Locked Tomb series as books about lesbian necromancers in space. What more do I need to say?
A Witch's Guide to Spellcraft
A "101" book that doesn't actually suck. It's actually astounding to me that Althaea isn't raved about as much as I think she should be. She's very specific, nothing is vague, and her practice and writing style are unapologetic and no-bullshit. If you vibe, her Patreon membership is also rave-worthy.
Treading the Mill
Very informative and atmospheric book about traditional witchcraft. One of my faves that I've read.