Sketchfab Download API - A search bar for the 3D world
CGTrader - CGTrader is an online marketplace at which artists can sell and buy Revit and 3D models.
MasterpieceVR - Powerful VR sculpting & painting tool
3DOcean - 3D Models & Accessories From $1 for 3D Models, Textures, Materials & Shaders, 2D Concepts...
Vectary - Vectary is a free, online 3D modeling tool and sharing platform.
TurboSquid - TurboSquid offers 3D models for professionals.