My most used Blender addons #4:
- Shaders Plus by SMOUSE
Glass, water, oily metals are just made extremely easy with these shaders. You would be surprised how much I end up making those.
Also very performant and comes with a bunch of presets to get you started.
Even though my own Material addon has a glass shader, I mostly use that one when I need simple glass with surface imperfections. For anything more complicated like light dispersion or caustics, I use Shaders Plus.