At the outset, it should be clear that this is a highly personalized list. It's not a list of the most important or influential books in numismatics. The venerable Redbook would probably top that list. It's simply a list of some of the coin books I've enjoyed for many years, and never tire of occasionally picking up and browsing again. For the most part, they are generalist works as my interests lie in the broader picture of numismatics as opposed to the specific. So, with that, here are a few of my all-time favorites.
1. Coins in History by John Porteous (1969). This is both a numismatic as well as a history book. I really cannot summarize it better than its introduction, which follows:
"Coin collectors tend to be interested in rare coins. This book is about the common ones. The great interest of coinage is that it holds up a sort of mirror (sometimes only a dim one) to history, especially to economic and social history. The coins which do this are above all those which were traded and spent again and again, whose names are written in every banker's ledger or housewife's accounts book; Shylock's ducats, for example, or the Pied Piper's guilders. It is these, considered against the background of the rise and decline of coinage a monetary instrument, which are the subject of this work."
2. Penny Whimsy by Dr. William Sheldon (1958). A revision of his 1949 work Early American Cents, Sheldon not only made a compelling case for collecting the early large cents (1793-1814) but (for better or worse) also introduced the numerical grading system which we use today. Part one of the book is a real delight and is a must-read for any serious numismatist.
3. The U.S. Mint and Coinage by Don Taxay (1966). Despite being written over 50 years ago and possibly superseded by subsequent research, this book remains one of the best overviews of the history of U.S. coins ever written. It is not without a few shortcomings; the branch mints were given short shrift, but no work tells the early story of the struggles of the Philadelphia mint any better.
4. American Coin Treasures and Hoards by Q. David Bowers (1997). A single work from the greatest and most prolific numismatic author ever was a tough choice, as anyone of a dozen or more of Mr. Bowers' outstanding works belongs on this list. This one, in particular, was one of my favorites as it combines loads of numismatic history with a healthy dose of drama and mystery.
5. My final choice is not even a full book, but only a couple of pages from one. The book is Holinshed's Chronicles, written by Raphael Holinshed and published in London in 1577 and again in 1587. There is a short section at the end of the "Second book," entitled Of the Coins of England in which is given a short history of English coins. To my knowledge, this is the earliest discussion of any numismatic history in the English language. Fascinating stuff.