Currently I am working really hard on my new Project The-BlenderSauce-Vault.
The-BlenderSauce-Vault is a collection of useful things for your work with Blender and other 3D Software. In the Vault you will find Procedural and Texture based Materials for Blender, mapped Textures, Alpha Brush Sets, Normal Maps and HDRIs(not yet but soon). Everything you find in the Vault is free for Download without registration, subscription or any other costs.
It is all under the Creative Commons License (CC-BY 4.0) or Public Domain (CC-0)