Unity finally has a shader graph system. Here I will try to keep track of all the useful nodes people are developing.

shadergraph-custom-nodes by andydbc

• Easing Functions
• Procedural Star

shadergraphextensions by simonwittber

• 3D Bars
• Billow Noise
• Cellular Noise
• Checker Noise
• Fractal Noise
• Marble Noise
• Multi Fractal Noise
• Ridge Noise
• Volume Noise
• Voronoi Noise
• Worley Noise

ShaderSubGraphLibrary by beinteractive

• Dotrize

ShaderGraphExtensions by beinteractive

• Simplex Noise 3D
• (Experimental) Main light parameters.
• (Experimental) Realtime Shadow.

shader-graph-nodes by gilescoope

• Signed Distance Function nodes
• Truchet nodes
  • Square
  • Triangle
  • Hexagon
• Composite nodes
• Halftone nodes
• Lab Color nodes
• Pattern nodes
  • Zig Zags
  • Sine Waves
  • Round Waves
  • Spiral
  • Whirl
  • Dots
• Pixel Perfect nodes
  • Line
  • Circle
  • Polygon
• Complex nodes
• Quaternion nodes