I recently finished Richard Mouw's Calvinism in the Las Vegas Airport, which is his approachable apology for Calvinist theology. As a Calvinist who is only beginning to learn the theology and history of this tradition, I found the book to be a helpful summary of how Mouw allows this tradition to shape his thinking and his life.
The only part of the book which really changed my thinking was his emphasis on "Heidelberg One" as the starting point for understanding Calvinism. His argument is that a person's acknowledgement that they are utterly dependent on God for all good is the central element of Calvinism, and that the doctrines of the Cannons of Dordt, while a defining element of Calvinist theology, are less widely applicable to our lives.
My only disappointment with the book was Mouw's sometimes overly apologetic tone. He seems to recognize that Calvinism is somewhat unpopular, and spends a lot of time acknowledging and dealing with the difficulties that people have. While this is helpful, he spends less time explaining the positive aspects of this theology – the freedom that results from recognizing God's ultimate sovereignty. Overall, however, the book was a very easy read, and does a good job of explaining the importance of Calvinist theology for his own life (and presumably his readers' lives).