Top 20 NuGet common Packages

Helpers for WebApi
URMHC Common
Base core library
Package Description
Class library containing common abstractions to support development of common forms.
Testing distributed framework
A robots.txt parser written in c#. This is an unofficial fork of NRobots.txt on codeplex with extended functionality. For full documentation see https://nrobots.codeplex.com/.
Common.Serializer provides a simple serialization abstraction to switch between different implementations
A library that I tend to create for just about every project... contains extensions and other things that I find useful, you might too (or maybe not).
A library of core helpers, extensions, constants, enums and other useful things for .NET Web projects.
A library of core helpers, extensions, constants, enums and other useful things for Sitecore CMS projects.
Provides custom types, helpers and extension methods for Visual Studio extensibility, particularly its Team Foundation part.
Antix HTML Common Code
Common interfaces describing an abstract template engine.
Reef Common Infrastructure
bysun common class library
FFXIVAPP Common Controls and Helpers
Package Description
This package contains a control consisting of a read-only text field with a header for cross-platform applications built with the the .NET framework with support for UWP, Android, iOS and Xamarin.Forms applications.
A long description of the package. This shows up in the right pane of the Add Package Dialog as well as in the Package Manager Console when listing packages using the Get-Package command.