Top 20 NuGet Unit Testing Packages

Framework to automate tests using Objectivity.Test.Automation.Common with xUnit
Machine.Specifications is a Context/Specification framework geared towards removing language noise and simplifying tests.
An open source code coverage tool (branch and sequence point) for all .NET Frameworks 2 and above (including Silverlight). Also capable of handling 32 and 64 bit processes. Use ReportGenerator 1.9 for best viewing results (also available via Nuget).
Unit testing framework for Sitecore.
Acceptance Test Driven Development and Executable Specifications for .Net
Test harness for Nancy applications.
Redbridge C# Windows Integration Testing Library for unit testing full service architectures
Testing helpers for using FakeItEasy with EntityFramework.
Logs test run information to PocketLogger and, optionally, to a log file.
Generators include: random numbers, currency amounts, coin toss, LUHN passing credit card/account number/sort codes, e-mail, URL, male/female names, lists, IP address, UK mobile and landline phone numbers, UK National Insurance (NI) numbers, relative date/times, and many more.
A C# class library that handles mocking, test data generation, and validation.
An implementation of IWebDriver in a mock class which does not open a browser and returns predefined elements and data. Used for unit testing selenium based frameworks
Testing helpers for using Ninject.MockingKernel.Moq with EntityFramework.
Testing helpers for using Ninject.MockingKernel.NSubstitute with EntityFramework.
Run NUnit tests in a separate application domain.
Generates valid, readable C# from an expression tree, and can annotate that code with runtime values. Useful for e.g. code generation and unit testing assertions.
TestKit for writing tests for Akka.NET using xUnit.
Package Description
NUnit attributes extenstions for Allure
Project and item templates containing basic NUnit 3 Test Project.