I typically use around 1,000 polys for a base human model, this can go up to 10,000 for a hero character.
However most of my games feature quite a lot of screen content and in these instances I preffer to work with lower polygon objects in the 300-400 region, although a human model at this polycount is always going to look square, artists like Soyuz are able to do more with 400 polys than I could, or even half way decent modellers like Raven, and if your lucky enough to have access too or to be one such artists then your in for a much easier time dev'ing games.
How you choose your final polycount though should be much different to this process:
If you have a game which requires 50 humans onscreen, and you have the programming skill to make 50x400 polygon models run smoothly but dont have the skill to make 50x600 polygon models run smoothly. Then you should model your humans to be 400 polygon.
If you cant make humans look good at 400 polygon but you can at 600 polygon, then you should make them 600 polygon and modify your game design accordingly.
Pneumatic Dryll
