This book presents condensed matter field theory from a very modern standpoint, using the language of (euclidean space) path integrals. In addition to a good discussion on mean field theory, the includes more modern topics, and includes extensive discussions of the renormalization group, topological field theories. Furthermore, the coverage is very intuitive, but simultaneously does not shy away from the more subtle technical details. The authors are also careful to point out and explain potential points of confusion. Finally, there are a number of excercises (each accompanied by a brief solution, which makes the book great for self-study!).
In summary, this book is the most readible introduction to condensed matter field theory that I've come across. It's a necessary, and welcome addition to the current literature.