Awesome
EEVEEToon
NOTE: This is outdated and may not work with the latest Blender releases
Set of nodes and sample shaders to make NPR shading in Blender Eeevee easier
Head over to Releases and download the latest release. Inside the zip file you'll find another zip which you can add to blender's add-ons (Edit->User Preferences...->Add-ons->Install Add-on from file...).
This is work in progress, as is Blender 2.8.
To use it, simply go to the Material tab to append the group nodes. The Base Nodes are for building custom toon shaders, the Sample Shaders are ready-to-use shader group nodes.
Here is an example of a shader made with the base nodes: