Turbosquid
3D models, texture maps, materials and other graphics resources designed for use in 3D applications.

The 3d studio
Free and purchasable 3D models resource, in 3DS format.

Renderosity
Comprehensive resource for 2D and 3D artists, with free and purchasable 3D models, Tutorials, news and Digitial Art.

3D Valley
Free 3D model resource, as well as textures and turtorials.

3DM3
Free and purchasable 3D Model resources for computer graphic arts industry.

3D Total
2D and 3D resource for free and purchasable models, as well as galleries, products and up to date news.

Google 3D Warehouse
Free 3D model resource for Google Sketchup files