A list of Unity resources I find useful or interesting.
ParrelSync - Test multiplayer within the editor.
Piranha - A simple tool to make rigidbodies swarm a mesh in Unity.
Smart-Hierarchy - Human-friendly hierarchy for Unity.
UniMob - Simple and scalable state management for Unity.
GameWork - Generic code and tools to build the basis of a framework to develop Unity based games.
Morrowind Unity - Recreation of Morrowind game in Unity.
Heartbeat - Unity Rhythm Game with Variable BPM Mechanics based off of Stepmania's File System.