This is by far the best name book I've come across. It has enough names that it offers a wide variety of choices, but not so many that my eyes glaze over. I also love that each name has suggestions for similar names, so if I find something I almost love I can get more ideas. It also has a little graph of popularity over the last century, and current rating.
Yes, the name is a little silly. Wizard? But the facts are solid and the lists are all helpful, too. No lists of terrible celebrity baby names (I don't think anyone is planning on repeating the name Moon Unit) or future parolees or most likely to climb Mt. Everest.
If you have a specific, unusual name you want more information about, sure, consult the book with 50,001 names. But if you're not sure which direction to go, get this book.