Characterz - Biggest diverse mix and match 3D illustration library
Shapefest - A massive library of 3D shapes for everything!
H A N D Z - Free 3D illustrations of diverse hands gestures
PixCap - A browser-based 3D animation editor and assets library.
Khagwal 3D Illustration Library - Free 3D illustration library for web & mobile app designers
Wannathis - 3d illustrations and freebies