If you've been looking for 3D models of cars and trees for your exterior architectural design. Furniture and interior design appliances. Below are sites with a wide range of free 3d models.
http://archive3d.net/ - A large 3D model archive. Models are categorized by type and brand.
http://www.archibase.net/ - A large archive of 3D models. The models are classified by style and brand.
http://www.3dxtras.com - Limited to 15 downloads per member
http://www.fritzhansen.com/chairs - A furniture company offering 3d versions of their products free of charge
http://www.creative-3d.net/free3D.cfm
http://modelsbank.3dm3.com/
http://gfx-3d-model.blogspot.com/ - I've been to his blog, and I've seen a lot of high-quality templates on this site. I really like his collections of cars and architecture.