Kindred - Octavia E. Butler
Brutal and perfectly executed sci-fi. Doesn't waste any time on the well-worn tropes of paradoxes or stealing a sports almanac. I'd usually find the lack of exposition to be annoying - but here the story was so powerful that I had no time to miss it.
Published 40 years ago, but hasn't aged a day. It perfectly captures the slow descent in the acceptance of abuse.