That last one with the lighting setup is looking top notch. Everything has meshed well and you can really see something malevolent behind the eye. (I like the zombie above too, with the cataracted eye and the ‘look I’ve just been hit in the head with a piece of two-by-four’ grin.)
Maybe one suggestion would be to kill the global specular material and just paint on the specular where it is needed on the highlights.