Table of Contents:
The Bridges of Konigsberg
The Value of Pi
Prime Numbers
Famous Paradoxes
The Problem of Points Proof of the Pythagorean Theorem

Jacobs, H. Mathematics: A Human Endeavor. New York. W.H. Freeman and Co. 1982. This isn't a math history book per se, but since it's the best math book ever written, I figured I'd include it. If you are reading this page, and you don't have this book, go and get it. Now. Borrow it from the library, buy it, whatever, just get it. It provides enjoyment and educational value for levels 6th grade through Fields Medalist. There is some math history mentioned in it too, but mostly it is a voyage through the various fields of mathematics, starting from scratch and working up to surprisingly high levels. Just open up to the first section, "Mathematical Ways of Thinking," and start reading "The Path of a Billiard Ball." You will soon discover that a) you want to keep reading, and b) you actually want to try the exercises. If you are going to teach a general math course, you should use this book. If you are going to an island for the rest of your life and can only take one book, take this book. Enough said.
Simmons, G. F. Calculus Gems. New York. McGrawHill. 1992. (subtitled Brief Lives and Memorable Mathematics). A rather misleading title, yes, but also a very good book. Divided into two sections: part A contains 33 short biographies, part B an explication of 26 pieces of 'memorable mathematics'. A very interesting read, but tough to use as a text due to the varied fields touched on by part B and the varied levels of advancement needed to understand the different pieces. 