Hidden Features of C#?

This came to my mind after I learned the following from this question:where T : structWe, C# developers, all know the basics of C#. I mean declarations, conditionals, loops, operators, etc. Some of us even mastered the stuff like Generics, anonymous types, lambdas, LINQ, ... But what are the most hidden features or tricks of C# that even C# fans, addicts, experts barely know ? Here are the