Well the Book hhat comes to mind that most people have not usually heard of is not that obscure, but was somthing that opened my eyes to a whole different way of thinking. The Book you Say?
Surely You're Joking, Mr. Feynman! (Adventures of a Curious Character)
by Richard P. Feynman & Ralph Leighton.
It cronicles parts of the life of the Nobel Prize winning physicist.
When I recieved it as a gift on my birthday, I first refused to read it becsuase I Thought it would be a dull read (D'uh! The minds of 10yr olds)
However once I started reading it, I couldn't put it down.
Up until then Scientist's to me were just boring old men in lab coats that came up with things I had to learn by rote. Reading this book bought them to life for me as human beings, as people not icons.
But most of all, it made me laugh so hard that at times, my ribs hurt.
The cheerfully irrelevent way in which Feynman went about doing things makes you appriciate his genious even more.
And as you go back and reread parts of it, it can really make you think.
and so by virtue of being on my Third Copy (Worn out, and Lost The previous 2) I would heartly recommand this to anyone as a great read, and a good introduction to some of feynmans concepts for non scientists.
I'm Don't this one is available as a E-book, But this is one I would say is worth having in hard copy just for the rereadability factor.