I can’t answer your question about Fodors or Frommers as I have not used either. I do concur with others about Lonely Planet but it is not for everyone. Some of the Lonely Planet books have “on a shoestring” under their title and they are budget guide books. Others are all purpose guide books. I use Lonely Planet during 90% of my travels but 90% of my travel is to 3rd world countries.
When I pop over to Europe for a long weekend I usually use Time Out’s city guides. I have used both the Paris and the London Time Out Guides and I highly recommend them.
------------------
The world is a book, and for those who do not travel, read only a page.
-Saint Augustine