Mixamo is an Adobe product and all the 3D models available at Mixamo are free to use for personal and commercial purposes.
Itch.io is a market place for indie games. You can buy games for all platforms on itch.io. It also has lots of game assets hosted on it for free.
Artstation is complete store to buy creative collections. You can buy tutorials, game assets, pictures, art brushes, 2D art, books and comics.
CGTraders is a huge collection of premium 3D models. Though most of their assets are paid they also have a collection of free 3D models.
If you are looking for 3D models then TurboSquid should have definitely crossed your search result. It’s a collection of free and paid 3D models for all type of purposes.
Gameassetsmarketplace is very similar to any game asset store. They have all required free game assets like 2D, 3D, audio, GUI, VFX.
GAME ASSET MARKETPLACE
Game dev market is an indie game asset store when indie developers can sell their assets. It has collection of 3D,2D, GUI and audio
Kenny is a collection of different types of free game assets. They include 2D, 3D, audio, environment and UI assets.
Sketchfab is a collection of 3D models of all sorts. Their 3D models can be used for different types of applications like 3D printing and games
Free 3D is an awesome place to get free 3D characters. But, it’s not all Free. Even though the name is Free 3D not all models are free.