Top 20 NuGet helper Packages

Persistence test helpers for CoreDdd library
The Relativity API Helpers include interfaces that you can program against when developing agents, custom pages, and event handlers. They provide the ability to write common code for sharing across these extensibility points, simplifying your development processes and facilitating code reusability.
MCART for Windows Presentation Framework
MCART .Net Standard Edition
Experience is a useful, clean and fast functions library for .NET Projects. You can find the project wiki here:
Helpers for CoreDdd library
A tiny helper library for creating database integration tests
A set of generic helper methods and classes for .NET Framework
MCART Lite Edition
Helper for UWP apps and libs
Some utilities by VPKSoft.
A jack of all trades and master of none. UtilitySharp provides helper classes with useful and powerful methods for things such as strings, datetimes, randomness, and numbers so you don’t have to reinvent the wheel. As such, UtilitySharp strives to be the one library that you will always download fo...
Test helpers for CoreDdd library
A collection of useful helper extension methods
XmlSerializerHelper serializes and deserializes any .Net object from/to XML. It internally uses XmlSerializer which is part of the System.Reflection namespace. On top of XmlSerializer it adds a feature to preserve original type information.
Genesis.Logging is a library for application authors (not library authors) that facilitates performance-focussed logging that can be compiled out of performance-critical builds.
.NET Core Common Helpers. Many helpers such as: CmdHelper, Log4NetHelper, TypeHelper and JwtHelper and so on.
Helper for Box Integrations
Provides the layer for MongoDB operations over .NET driver
Genesis.Repository is a library that makes it simpler to implement database repositories, particularly within a mobile application.