Top 20 NuGet monogame Packages

Cocos2D-Mono for iOS
A tool to package MonoGame and other .NET Core applications into several distributable formats
Basic classes to assist in management of multi language content
An Entity Component System to make MonoGame more awesome.
Support for Tiled maps to make MonoGame more awesome. See http://www.mapeditor.org
Cross-platform UI control library for MonoGame
Reactive data objects for extending the dotnet reactive library, unirx provides this out of the box
Input library for MonoGame.
MLEM Library for Extending MonoGame combined with some other useful libraries into a quick Game startup class
LDtk importer for Monogame
Load your splines with the ContentManager of the MonoGame.Framework.
MonoGame library for taking screenshots and exporting gameplay to an animated gif
A set of view based conventions to assist with separating view from logic/data
EcsRx plugin to add the notion of computeds to the system
A reactive take on the ECS pattern for monogame developers
MLEM Library for Extending MonoGame extension that ties in with MonoGame.Extended and other MonoGame libraries
A mouse, keyboard, gamepad and touch ready Ui system for MonoGame that features automatic anchoring, sizing and several ready-to-use element types
A tool for MonoGame that automatically handles adding assets to the Content Pipeline project
Simple loading and processing of textures and other data for MonoGame, including the ability to load non-XNB content files easily
A suite of persistence related features and helpers to allow you to make complex data pipelines, as well as saving/loading entity databases