its a little hard to understand by what you mean by "bad looking polygons". I assume you are talking about the stretching of polygons around the joint areas, as there is only single bone per vertex (elbows, knees, hip)

There is a very careful way to setup these joint areas to minimize or even prevent the polygons stretching. I dont have the picture, but im sure someone on the forum should have it. In short, it shows that adding a few extra polygons around the joints that are specifically made to stretch can minimize the problem of a single face(s) stretching too far during an obtuse rotation.

I wouldnt create the model out of seperate meshes reguardless. Thegamemaker's comment is absolutly right. An unclosed mesh dosent have uniform lighting since it is actually seperate peices, and can look downright ugly.

You may have to rework your joints to accomadate stretching, and start making any later models with the mindset of building the joint polys to stretch.

EDIT:

found it: