Top 20 NuGet testing Packages

SlickTL is a library that can be used to help with creation of mstest test cases. It adds ini config parsing (from the fabulous Nini project), and it adds configuration of logging. Also included are slick specific pieces like annotations, and test steps for adding data to slick.
An NUnit wrapper for the Given BDD framework
Gets you up and going with a DotNet app quicker by providing interfaces for commonly used mapping techniques.
NTestCaseBuilder library samples. It will add some C# sample files into a folder 'Samples\NTestCaseBuilder' within the referencing project. These samples can be built and run, mostly as NUnit tests.
A simple way of faking NServiceBus hosted services
Handy base test classes and other extensions useful for TDD using NUnit.
.NET extensions and helpers for LINQPad.
The fastest and smoothest way to great architecture
単体テストで使うデータを .xlsx ファイルに記述して簡単に利用できるようにするための仕組みです。
NUnitLite provides a simple way to run NUnit tests, without the overhead of a full NUnit installation. This package contains a build of the NUnitLite runner for the .NET compact framework 3.5.
Specifications made easy.
Common AngularJs Selenium extensions. Part of RobustHaven.IntegrationTests
Should assertion extensions for the XUnit v1 framework
Should assertion extensions for the XUnit v1 framework
Seeed Component wrappers for Gadgeteer.Interfaces
Utility classes and extensions to facilitate common testing when using ServiceStack versions 3.9.*.
Fake implementations belonging to Gadgeteer.Interfaces
GHI Component wrappers for Gadgeteer.Interfaces
'native' GT and SPOT wrappers for Gadgeteer.Interfaces