Top 20 NuGet delegatecommand Packages

MVVM Framework for WPF
Makes WPF ViewModel classes smart by default. Implements INotifyPropertyChanged and DelegateCommands for auto properties, recognises dependent properties, connects property changed handlers, triggers validation. Supports virtual properties with Entity Famework.
.Net Standard libary which implements ICommand interface and provides Command and AsyncCommand classes that are tipically used to provide commanding behaviour to user interfaces. This particular library does not rely on CommandManager which is part of WPF, therefore it can be used with Xamarin and ...
Unit-Testable components for general .NET development
Common types for WPF / MVVM applications.
An async implementations of delegate command and other base common classes for WPF.
Prism seems to not develop any further ICommand implementation. This lib extends or replaces the existing Prism Commands.