For me, the most recent book regret is Dark Matter by Blake Crouch. Predictable from the get-go, bland, boilerplate sci-fi ideas, too many of these way-too-convenient plot devices just to push the story forward. I frankly don’t get the hype, and I am a pretty big science fiction guy.
Another one is Blink by Malcolm Gladwell. I read this in college and this whole book should have been a one-page essay. It was too repetitive, and the whole premise of “trust in your snap judgments and gut reactions” is way too simplistic and honestly stupid. Like all Gladwell books, it was anecdotal, superficial, and a waste of time.
Out of the books I’ve finished this year (aka not counting DNFs), I would say Letters to a Young Scientist. Rather than continuing the genuine, humble spirit of Letters to a Young Poet (its inspiration), the author used it as a platform to aggrandize himself and his particular career path despite the breadth of the scientific field.