Hi
Just to add to the confusion. I just bought the DK Eyewitness guide. In the past I've used all the previous mentioned guides. When I went to Turkey several years ago I used the Cadogan guide and found it very good. Last year I used the Blue Guide. These guides are less involved with restaurants and hotels and more is given to archetecture, museums etc. It depends on what your needs are.

Dummy's guide works well for us - combine that with a Fodors and maybe a Lonely Planet.