For hundreds of free static models (eg an apple) http://www.3dcafe.com/
NTU 3D Model Database has a massive database of wavefront free models:http://3d.csie.ntu.edu.tw/~dynamic/database/index.html
Turbosquid is a commercial site that sells 3D models but they also host free ones. You need to open a free account here.http://www.turbosquid.com/
Also from the NTU 3D Model Database but with pictures and also only has the first 1000 models from the database:http://www.skinhat.com/freemodels
For actors (eg Quake, Half life models) - Currently down :http://www.planetquake.com/polycount/
