Top 20 NuGet extensions Packages

Timely (or Timely Extensions) is a small Library that gives you some shortcuts for Dates and TimeSpan. With these you can do stuff like "15.February(1996)" or "16.Minutes() + 20.Seconds()".
Essential tools and services for everyday projects
C# Extension Methods *** This package is for "strongly-named" assembly/projects.
Paaticles.Community.Extensions.Views
Paaticles.Community.Extensions.Core
Package Description
Basic extensions for string, int, Linq, List, Object, Properties, StringBuilder, and Dictionary to simplify routine tasks.
Basic connection creation and disposal abstracted away so that one can focus on their business logic.
Extensions to the ResultMonad package. For more information see http://csharp-functional.readthedocs.io/en/latest/extensions.html.
aquirrel base lib. Extensions
From the Selenio project. Plug this HTML reporter to generate rich step-by-step reports in your test executions.
Awesome lib with extension utilities
Mef Extensions
Simple set of Lazy extensions. Code savers like: Lazy.Create(...) which allow for type inference
Provides helper and utility types, classes and extensions.
C# Extension Methods