Jon has done it again Now with great new chapters on Dynamic, Code Contracts and more: http://manning.com/skeet2/
C# In Depth was a great book to gain deep understanding of the C# language (up to version 3.0) and how to effectively use its features. The second edition is more complete with full coverage of C# 4.0 and new additions to the .NET Framework (Code Contracts). Code Contracts isn’t strictly a language feature but it’s definitely a great tool in any C# programmer’s toolset and as always, Jon covers it exceptionally well.
The Second Edition is now available for pre-order. If you’re in the .NET online community, chances are that you’ll hear about the book when it gets released. I really recommend it.