Top 20 NuGet extensions Packages

System.IComparable extensions.
System.IO.DirectoryInfo extensions.
System.StringComparison extensions.
ExtraLINQ provides additional extension methods for working with .NET collections.
Some helpful extensions for LINQ
PagedList extension for ASP.NET MVC (razor) with custom html-pager for bootstrap.
A helper library of BindingConverters, MarkupExtensions, and other utilities for building XAML applications for WPF 4 & 4.5, Silverlight 4 & 5, Windows Phone 7.5 & 8, and Windows 8.x.
Generic GetService[T] and GetServices[T] extension methods for the System.IServiceProvider interface.
Library to enhance the given capabilities of Windows Forms applications.
Provides an easy way to create tile, badge and toast notifications.
Some helpful methods and utilities for ASP.NET MVC Application
An simple library for modifying File Associations from .Net code.
LinqEx contains a set of extension methods to runtime objects, mainly to enumerables. These extensions can help you increase your productivity.
Methods Extensions for object, string, datetime, IEnumerable, IQueryable, and many others
C# set of useful extensions methods.
The class4js module is for class-driven development in JavaScript. It allows to emulate classes in JavaScript. Module is based on ECMAScript 5 standart and implements open/close principle: "A module should be open for extension but closed for modifications".
.NET extensions and helpers for types in System.Core.
.NET extensions and helpers for MSTest.
Simple caching extension method for Service Stacks ICacheClient. Gets or sets the cache if a value is not found based on an Action passed in. Simples.