Top 20 NuGet mocking Packages

It's faking amazing! The easy mocking library for .NET that works great in C# and VB.NET alike. No need to know the difference between a stub, a mock or a spy, everything's a fake! The easy to use, refactoring friendly API makes faking a breeze.
Moq is the most popular and friendly mocking framework for .NET.
NSubstitute is a friendly substitute for .NET mocking libraries. It has a simple, succinct syntax to help developers write clearer tests. NSubstitute is designed for Arrange-Act-Assert (AAA) testing and with Test Driven Development (TDD) in mind.
The most powerful free mocking library available for .NET developers.
It's what a Mocking Framework should be. Powerful. And it's the first of its kind.
Pester is testing framework for PowerShell, written in PowerShell.
Autofac extension supporting generation of FakeItEasy objects.
Fody add-in for changing all members to virtual.
Library that provides methods that will help you with mocking Entity Framework Core.
Utilities to streamline unit testing in Dynamics CRM 365 by faking the IOrganizationService against an In-Memory context which runs blazing fast.
Replace any .NET method (including static and non-virtual) with a delegate
A set of extension methods for mocking HttpClient and IHttpClientFactory with Moq.
Smocks is a library for mocking the normally unmockable. It can mock static and non-virtual methods and properties, amongst others.
A library for creating Self-Initializing Fakes.
Dynamic mocking framework for .NET
Fast and easy testing of BizTalk server integrations by mocking the communication to and from them.
Moq auto mocking integration for Stashbox.
Unit testing framework for Sitecore.
Unit testing framework for Sitecore.
Utilities to streamline unit testing in Dynamics CRM 365 by faking the IOrganizationService against an In-Memory context which runs blazing fast.