CGTrader - CGTrader is an online marketplace at which artists can sell and buy Revit and 3D models.
Reshot - Tons of uniquely free stock photos. Handpicked & non-stocky
3DExport - 3DExport is a 3D model marketplace where you can buy and sell 3D models, CG textures and digital objects for 3D printing with royalty free. Professional 3D models - 3DExport.com
UpLabs - The best material design, iOS & web resources, every day
TurboSquid - TurboSquid offers 3D models for professionals.
Mixkit - High-quality stock videos that are completely free.