ambientCG is website providing free textures, materials, 3D models and other resources for creating games, movies, and anything else related to the world of computer graphics. All assets are available under the CC0 License.
You can start using ambientCG.com immediately. No registration required. You can browse the list of assets and search for an asset using keywords or the dropdown menus near the top of the page.
Most assets come in a variety of pre-generated sizes and formats. Simply pick the files you would like to download.