Collins Bird Guide/Birds of Europe (Svensson, Mullarney and Zetterström). This has been the standard in field guides for some time, and this second edition goes from strength to strength. The guide covers all of Europe, North Africa, and part of the Middle East (it is very good for Israel, for example). Excellent plates and range maps with updated information. This is still compact enough to take in the field, even if visiting just the UK or France. The famous Collins guide is also available in large format but it is no good in the field (far too bulky). The app version of this guide is highly recommended and has all the bird calls.
Birds of Europe with North Africa and the Middle East (Jonsson). The artwork is very nice, but maybe not the best suited to a field guide. The arrangement is a bit spotty as well. The range maps are fairly good, and this book does cover the species in North Africa.