Ever wanted simple syntax for slicing out a part of an array, string or span? Now you can!
One of the new features being proposed in C# 8.0 is to introduce Records. They are essentially a very lightweight class that is a collection of fields.
One of the new features being proposed in C# 8.0 is to add support for virtual extension methods (methods in interfaces with concrete implementations)
One of the features being discussed for introduction in C# 8.0 is Nullable Reference Types. A proficient C# Developer might say "What?! Aren't all reference types nullable?"