Pylon Rogue's Rim Light in Unity (from my job at QuantumSquid)
One of my big contributions to our Pylon Rogue project at Quantum Squid was adding a rim light feature to the character shader in our project. Rim lights are extremely simple, but implementing one in the extremely complex shader we had was tough. I had not worked a lot with vertex/fragment shaders much, but in about one work day total I managed to track down the needed variables in the shader code (the normals, and the base texture color, the latter of which was the hardest) and output a rim light to the emissive output of the shader. This was a huge improvement to our games visuals, and I applied the rim light to all characters (besides the fire and ice golems, which were already lit and didn't need them), all enemies, and to breakable objects. As you can see from these images, these rim lights help characters stand out from the background significantly in dark areas, which both looks better and helps the game play better as well.