Top 20 NuGet extensions Packages

Linq join to string extensions methods
A set of C# extension methods and helpers.
Extension methods for mostly modifying arrays. This package is for direct inclusion in a C# project (compatible with C# language versions 6 and above). All types will remain internal to the project.
A collection of extensions for asynchronous programming.
Classes for extending the System.Configuration namespace.
A collection of useful, reusable Extension Methods for C#
Extensible Framework
Extend method ad object for string
A collection of extensions to C# projects
This project extended plug-ins provides you with convenience for your programs.
Azure Webjobs SDK Extension for Triggering a Group of Messages
A small toolbox - primarily used personally :)
星球DotNet扩展库
Use this library to check whether the console is open. Commonly Used Types: ConsoleHelper
A simple fluent logging library built on existing System.Diagnostics tracing API
This package contains built-in behaviors for Xamarin (Android / iOS) applications and the core classes to create new ones. Get more information about the Behaviors Toolkit for Xamarin at https://github.com/ThomasLebrun/XamarinBehaviorsToolkit
A library full of extensions for simple things and simplification of complex built in functionality such as encryption and email sending.