Top 20 NuGet unit Packages

Easy to use, small, SignalR Core unit testing support with MSTest and Moq. For Nunit or xUnit version see my github.
HttpClient extensions to test REST endpoints.
Simple framework to write assertive unit tests
Code.Generation.Roslyn facilitates code generation driven by fit for purpose custom attributes.
This package needs to be installed in order to execute JazSharp unit tests in visual studio and the dotnet command line.
JazSharp is a unit testing and method-level mocking framework heavily inspired by Jasmine (JavaScript). Major benefits of using this framework over others is that you can mock non-virtual and static calls removing interfaces and dependency injection as requirements for effective unit tes...
ef and dapper repository.
Allows you to identify Domain Models and their relationships to their peer Models, which it then generates a Repository Pattern suite that complies with the SOLID Principles and other Best Practices. Automatically generates an effective set of Unit and Integration Tests.
My Tested ASP.NET Core MVC Newtonsoft JSON components.
Moq integrations library to aid in structuring unit tests to help enforce design and behaviours during development.
IcuBlazor: Tools and components for Blazor development and testing
Mcs.AspNetCore.TestBase
For C#/VB Universal Windows code (UWP), use UnitsNet instead. This is a Windows Runtime Component with reduced functionality to support all UWP languages, such as JavaScript and C++, and other runtime components.
A .NET unit test runner for the console/terminal.
Provides base implementations of an EF Core based repository (CRUD operations) and Unit of Work class.
Provides base implementations for a DAL-level entity, mapper for mapping between DAL and Domain entity and base Unit of Work class.
Makes it easy to work with lengths, when multiple different units are involved