"Fundamentals of Physics" by David Halliday, Robert Resnick, and Jearl Walker. My personal favorite textbook of all time.
Most of my other textbooks were relatively boring such that I never really wanted to read them in the first place, but "Fundamentals of Physics" starts with "fun", and each chapter starts with an anecdote that motivates the reader to want to learn more. The facts and formulas are obviously useful since laws of physics don't change all that often, but the really interesting bits are all these side stories that made use of these laws, including lots of daring stunts from physicists. It was a lot more than just a textbook.
Lots of textbooks fall in the category of expensive heavy objects that instantly become dead weight when the academic year is over, but "Fundamentals of Physics" have remained useful for many years after my final final exam. In fact, they have literally supported my photography hobby throughout the years. Here is a sample:
https://photos.app.goo.gl/g4vHqJiKDgzaA6mA7
With the imminent end of Google+, I thought I would take this moment to thank the precious and timeless helpers who have mostly been hidden from public view. Next time you see something interesting, remember those who are just outside of the camera view that have contributed massively to making things work.
Previous (2019-03-26): "Eromanga Sensei" volume 11 by Fushimi Tsukasa
Next (2019-05-19): "Hamamura Nagisa no Keisan Nooto" volume 9 by Aoyagi Aito