I would recommend Kindred. I didn't really feel engaged by the first third or so, but found myself unable to stop after a while.

Seems odd to say I enjoyed it, but I did really appreciate it. I appreciate how the relationships between characters, with the institutions of slavery, farming, with their time and place, are complicated.
Not that they're difficult to understand or full of twists and changes—though they can be—but that the author managed to build them up in a way that made sense, but also looked all wrong when I looked up from the book and thought about it. Reading it was a process of acknowledging some unspoken assumptions of mine that showed me how simple or weakly-considered my own understanding of slavery and social structures of the time may be.