Following are the top-selling C# software development books of 2008 according to the Amazon.com sales rankings:

Pro Silverlight 2 in C# 2008 (Windows.Net)
by Matthew MacDonald
Sales Rank: #2447
Pro C# 2008 and the .NET 3.5 Platform, Fourth Edition (Windows.Net)
by Andrew Troelsen
Sales Rank: #3585
Pro WPF in C# 2008: Windows Presentation Foundation with .NET 3.5, Second Edition (Books for Professionals by Professionals)
by Matthew MacDonald
Sales Rank: #4923
Microsoft Visual C# 2008 Step by Step
by John Sharp
Sales Rank: #5086
More Effective C#: 50 Specific Ways to Improve Your C# (Effective Software Development Series)
by Bill Wagner
Sales Rank: #6556
CLR via C#, Second Edition (Pro Developer)
by Jeffrey Richter
Sales Rank: #8018
Expert C# 2008 Business Objects
by Rockford Lhotka
Sales Rank: #8723
Pro ASP.NET 3.5 in C# 2008, Second Edition (Windows.Net)
by Matthew MacDonald and Mario Szpuszta
Sales Rank: #13446
Head First C# (Brain-Friendly Guides)
by Andrew Stellman and Jennifer Greene
Sales Rank: #15385
Professional C# 2008 (Wrox Professional Guides)
by Christian Nagel, Bill Evjen, Jay Glynn, and Morgan Skinner
Sales Rank: #18528
Beginning ASP.NET 3.5 in C# 2008: From Novice to Professional, Second Edition (Beginning from Novice to Professional)
by Matthew MacDonald
Sales Rank: #20392
C# 3.0 Design Patterns
by Judith Bishop
Sales Rank: #27138
The C# Programming Language (3rd Edition) (Microsoft .NET Development Series)
by Anders Hejlsberg, Mads Torgersen, Scott Wiltamuth, and Peter Golde
Sales Rank: #31992
C# in Depth: What you need to master C# 2 and 3
by Jon Skeet
Sales Rank: #33047
Illustrated C# 2008 (Windows.Net)
by Daniel Solis
Sales Rank: #34308

 

NOTE:  Also see the Best-Selling .NET Books of 2008