These are all awesome books, all in their own way. What makes them stand out in my mind is that they teach in a way that helps you understand - partly lecture, partly storytelling, partly humor.
The Singer of Tales, by Albert Bates Lord
Makes you understand oral epic in a really new light.
A Brief History of Time, by Stephen Hawking
Cosmology explained in a way that you can understand it.
The Tao of Pooh, by Benjamin Hoff
Taoism explained by example. It does work as a book.
Never Cry Wolf: Amazing True Story of Life Among Arctic Wolves, by Farley Mowat
The movie actually was almost as good as the book.
Reading the Forested Landscape: A Natural History of New England, by Tom Wessels
Given to me by my wife for Christmas one year - a fabulous read. I talked about it for days and days and days. Actually met Tom at a lecture he gave along with a walk thru some woods. What a cool guy!
The Second Self: Computers and the Human Spirit, by Sherry Turkle
It's somewhat dated, and she's apparently added to her list of books on this topic, but when I first read this one (shortly after it was first published), I thought it an awesome explanation of why computer games attract, and how various online communities attract, and how the definition of self changes in the modern age. Definitely a good read. (Her more recent books are equally readable and interesting!)
On The Wing: To The Edge Of The Earth With The Peregrine Falcon, by Alan Tennant
First heard about it on NPR. Good story and insight into the falcon and two crazy guys that follow it on it's migration path. Lots of ranting on pollution and environmental exploitation and it's affects, but mostly a genuine insight into the mindset, life and drive of the migratory bird population and especially the peregrine falcon. Also an insight into the mind of a slightly twisted person - the fanatical author and his own wanderlust.
A Walk in the Woods: Rediscovering America on the Appalachian Trail, by Bill Bryson
Bill Bryson is a good read no matter what. He walks (parts of) the Appalachian trail with a friend and recounts their adventures, trials, tribulations, etc while filling in alternate chapters with a history of the Appalachian Trail. This one I listened to on an audio-book while commuting. A good story.
Other good books by Bill Bryson that I've enjoyed (both as Audio Books): In a Sunburned Country - a travelogue about Australia and A Really Short History of Nearly Everything - exactly what the title says: a history of the universe from the beginning to now.
Inside of a Dog: What Dogs See, Smell, and Know, by Alexandra Horowitz
A psychology professor examines what a dog's "umwelt" is like and tries to get us to understand our "best friend" a little better.
Merle's Door: Lessons from a Freethinking Dog, by Ted Kerasote
A wonderful story of an outdoors writer and his friendship with a dog he finds while on a white-water canoe trip in New Mexico. Instructive insights into dog behavior, and what it's like to live a really open and intimate relationship with a dog like this one. Wonderful as an Audio-Book.
Krakatoa: The Day the World Exploded: August 27, 1883, by Simon Winchester
I listed to this on my commute over a couple of weeks. Long, detailed, intimate and illuminating about a part of the universe I'd never seen before. It really is all about the history of Indonesia and surrounding territories with the volcano as the centerpiece of the story.
The Visual Miscellaneum: A Colorful Guide to the World's Most Consequential Trivia, by David McCandless.
An artistic and yet scrupulously detailed presentation of information in novel graphical forms. It's a favorite coffee-table book in our house since all ages find it interesting. I bought mine from Amazon when I ran across it looking for something else...
The Ashley Book of Knots Every Practical Knot - What It Looks Like, Who Uses
It, Where It Comes From, And How To Tie It, by Clifford W. Ashley
It's a wonderful innovative presentation of information in graphical form. A favorite coffee-table-style book - accessible to all ages.
Mother Nature Is Trying to Kill You: A Lively Tour Through the Dark Side of the Natural World, by Dan Riskin, Ph.D.
A detailed and very graphical exploration of how Mother Nature's goals are not exactly what we imagine them to be. Every story is backed by references to the scientific literature cited in the appendix. The descriptions of the widely ranging variety of successful strategies employed by vastly different species of animals and plants makes this book a delightful read. You'll be the hit of the cocktail party when you quote bits of this. Definitely *not* for the squeamish or over-visualizer.