If you want to include ISO3166 in your project, you can install it directly from NuGet
To install ISO3166, run the following command in the Package Manager Console
PM> Install-Package ISO3166
Country[] countries = ISO3166.Country.List;
public string Name { get; private set; }
public string TwoLetterCode { get; private set; }
public string ThreeLetterCode { get; private set; }
public string NumericCode { get; private set; }
public static readonly Country[] List = new[] {...};
Data source: http://en.wikipedia.org/wiki/ISO_3166-1
License: CC BY-SA 3.0