Unity Particle Pack 5.x (Latest version)
Note: this particle pack is compatible for Unity 5.5. Find the brand new Particle Pack for 2018 HERE! This pack of sample particle assets can be used in your games and to help you understand how to achieve certain effects using the Unity Particle System component and modules. You’ll find Fire, Explosions, Rain and other cool effects, free to download!
This package comes with an example scene that requires certain project settings to be automatically set in order to work correctly.
To use the example scene, always import into an empty project.
If you want to import these effects into an existing project without affecting your current Project Settings, make sure to uncheck the Project Settings folder in the Importer Window before clicking Import!
Details on this asset from the official Unity Store.