Thanks for all the replies so far guys, some great info.  A lot of this I have kind of picked up from place to place and on different threads.  

What I'd still like is some more visual examples of mesh that is particularly good or problematic from a topology/meshflow standpoint (are those the same?? terminology usually gets the better of me!).  

For example in the mesh that shrdavid posted on page 1, it looked, to me, that there could be issues in between the armpit and the breast...it looked like it could get a bit pinchy.. but I'm just guessing... I dont know how to spot/visualise these things without actually bending the model and when there are issues I dont know if they are the result of the way the mesh is built or the way the rigging is done or  whatever else might come in to play