So I was wondering if any one had made a list of darkfriends that are most important to the story. Im not talking about random man in EotW chasing after Rand and Mat. But those that among the lords, whitecloaks, Seanchan, etc,etc.

This page lists known darkfriends that were revealed up through Gathering Storm:: http://encyclopaedia-wot.org/organizations/darkfriends.html

the WoT FAQ also has a good discussion on who is (or is not) a dark-sider. I'd recommend snooping around there, depending on how far you are in the series?