Top 20 NuGet extensions Packages

A set of extensions for optimizing/simplifying System.Threading.Channels usage. Includes: ReadUntilCancelled, ReadAll, ReadAllConcurrently, WriteAll, WriteAllConcurrently, and Pipe operations. Part of the "Open" set of libraries.
PureActive Network Extensions
CaveSystems Extensions Library. This packages contains extensions methods for various .net classes, fast crc32, crc64, base32, base64 implementations and backports for older frameworks.
a collection of my useful extension methods.
Same sugar for sharp programers.
A set of classes and functions to ease our daily .Net development tasks.
Boilerplate code that can speed up your development
CB.System is a collection of common classes to solve frequently occurring challenges according to System.*.
A library to convert a dictionary out of a given object or an object out of a dictionary.
Provides a library of extensions helping to be more fluent when developing
A set of helper and extension methods to improve the developer's speed in coding.
TauCode extensions library
WebDriverWaitExtensions is a C# library that provides extension methods for Selenium WebDriver's WebDriverWait class, simplifying the process of waiting for specific conditions in web automation. It includes detailed error messages and supports the use of Condition objects for assertions.
Provides some useful extensions to .NET Standard, TinyCLR and .NET Micro Framework.
A collection of helpers and extensions.
This contains a very useful extension method for AutoFixture that allows you to OmitRecursion, (if a class has multiple nested objects, and/or self-reference, this simple extension method allows you to provent this from being an issue)
Handy toolbox with commonly used classes and extension methods.