Currently, Leviathan Falls, the last book in The Expanse series. I'm a little over halfway through. Which is a little bittersweet, since I've loved this series for a long time now, and I want to know how it ends... but also kinda don't want it to end.
Not sure what'll be next up, but probably one of Babel, The Kaiju Preservation Society, or The House in the Cerulean Sea, depending on my mood.