"C# 5.0 in a Nutshell: The Definitive Reference" has an impressive index, making everything quick to find despite it's size (over 1000 pages). Concepts are explained clearly and in-depth.
This book is not designed as a tutorial, but as a reference only. For someone who hasn't yet been introduced to C#, "C# 5.0 in a Nutshell: The Definitive Reference" is going to be hard to follow.
As with all "Head First" books, "Head First C#" is written with a humurous, casual style that keeps the reader engaged. The creative use of captions and images increase retention of the material.
"Head First C#" is hands-on right from the beginning. The reader has plenty of opportunity to use their new C# skills as they are guided through developing fun programs (such as games).
This book is only meant as an introduction to C#, which it does a fantastic job at providing. The fundamentals are well explained, which makes learning more advanced concepts far easier down the road.
Many errors have been noted throughout the book. Typos, poor (and sometimes wrong) wording of explanations. In the Kindle version of the book, the code is poorly formatted (such as missing white space).
The author, Jon Skeet, does not limit his explanations to "how" to do something. Instead he goes into detail about the history of the language and the reasoning behind every concept. Ideal for someone who likes to know the "why".