Howard Eves' textbook on the history of mathematics is well respected and regarded around the world. It contains not just the broad overview of mathematical history, but also some of the personal stories in the lives of mathematicians - some of which are quite amusing!

For example, opening the text at random I discover the story of Lejeune Dirichlet (of the Dirichlet Principle) forgetting to tell his father in law of the birth of his first child. The father in law, upon learning of the child's birth, commented that Dirichlet "should have at least been able to write 2 + 1 = 3." These personal stories break up the more "scholarly" information, and keep the reader always aware that these were real people with real stories, not just old black-and-white photographs in a textbook.

If you are a mathematics teacher (particularly at the high school level) keep a copy of this book on hand - it will provide you not just with history, but with interesting anecdotes which will help keep your classes a little more...alive!