Here are some old renders using early versions of Freestyle for Blender. These images were initial rendering results of mine by means of the new NPR rendering functionality tested just after the first Win32 build of the Blender Freestyle branch came out in September 2008. The character design was originally made by an anonymous artist.
These are renders with colored lines using pyMaterialColorShader() on top of shadeless surface colors. The style module used for these renders is available here in the BlenderArtists Freestyle thread. At the time when these renders were made, the Freestyle branch was based on the 2.4x code base and anti-aliased lines were not supported yet. A common workaround was to render a larger image than a final size and scale it down.
These are results of a constant line color combined with halftone surface colors by means of PyNodes. The halftone script used for these renders is available here in the BlenderArtists PyNode cookbook thread.