I know Mike G typically uses Preiser unpainted people. I have seen only photos from Artista and an Australian outfit doing detailed figures. Here are a few I have found over the last couple of years. For the most part the men are 6 scale feet, but the thickness of the people varies - making mixing look odd.
The cheap China sourced figures are reasonably good at fitting inside trains and vehicles - and through a window are fine. Woodland Scenic and Scene-a-rama are reasonably detailed. Does anyone know what the two sets are marked unknown? The ones on the top left are "soft plastic".