The first Moon book that I purchased several years ago was the book on Oregon. We made significant travel arrangements based on the information in that book and we were never disappointed.
An upcoming trip to Seattle/San Juans is based on the information in the Washington book. The real beauty is that the book leads you to the most likely area to visit, gives references to hotels, etc., then you can complete your research by reviewing up-to-date information about that spot/hotel online. We chose Orcas island for 2 days before heading to Seattle and I do not expect to be disappointed.
The authors are even-handed and complete --- they are not elitists, reviewing only the high-end accomodations. They have a good sample of a broad range of places. They point out lesser known restaurants and scenic spots as well.
I have found their advice in the Oregon, Washington, Coastal California and New England books to be quite excellent.
I have purchased quite a few different travel books in the past, but Moon Handbooks are my travel book of choice.