C# In a Nutshell
Peter Drayton invited me to work with him (and Joe Albahari) on this book during the pre-release/pre-1.0 days of .NET. Joe and his brother have since taken the book through numerous successive revisions, each of them better than their predecessor, but I'm happy to have been a small part of getting this pillar of the OReilly Nutshell legacy upright.
Publisher's page for the book