Physics/Astronomy
Encompassing everything from molecules to planets, the realm of physics is broad. Take a look at the micro, macro, and the future with some of these books.
Bad Astronomy, by Philip Plait
Astronomy is one of those things that everyone remembers learning about in school, everyone understands the moon and stars and planets...but that understanding is very, very, superficial (myself included). Hence, Bad Astronomy. He debunks myths and beliefs about astrology, moon landing hoaxes, and flat earth. More importantly, he gives cool explanations (that I can't remember the details at all) for why the moon looks bigger on the horizon, why the moon always faces the earth, and loads more moon facts. The moon is great. He's able to break down complex astronomical topics into easily understandable examples and diagrams...that I still can't remember.
Strange Glow, by Timothy Jorgensen
Jorgensen's ability to cram an extraordinary amount of information on the history of radiation is unbelievable. Examining radiation from the perspective of physics, medicine, and other fields, he discusses it uses and harms towards humans. There's so much I learned, such as how Hiroshima survivors were used to quantify the tolerable dose of radiation, or the effect of cell phones on brain cancer (there's no link). Incorporating both historical and current events, this story would be almost complete but it's still being told. An excellent book on a topic that is both fascinating and terrifying.
Physics of the Impossible, by Michio Kaku
Invisibility, Intergalactic Space Flight, and Time Travel: ideas that only work in science fiction, right? Not according to Michio Kaku! This book details many concepts detailed in science fiction that are assumed to never exist in our reality. Dr. Kaku dismisses this notion, and informs the reader of current and ongoing research being done in these fields, and the possibility of these concepts occurring in real life! Invisibility may be a reality in a few hundred years, but teleportation may take a little longer. Although many of the chapters involve subjects with complex physics, they are explained in an enjoyable and understandable fashion. This book gives you hope that someday, mankind will "boldly go where no man has gone before."
The Physics of Superheroes, by James Kakalios
Why is Superman so much stronger on Earth than the average human? It's simple physics, of course! Professor Kakalios teaches a class relating physics to superheroes, and he sums up his teachings in this wonderful book. Just like an intro physics class, he begins with mechanics, and works his way through electricity and magnetism. Each chapter focuses on a different aspect of physics, and relates it to a different superhero or villain. If you're a fan of comic books, physics, or both, this book is sure to keep you amused.
Note: the only annoying thing about the book is that he does his calculations in imperial units, instead of SI.