1. Edge (he'll improve slowly as the season progresses and definitely has opportunity)
2. Greene (the most upside, could split with Leon Washington if Thomas Jones struggles)
3. McClain (Rice is the lead back, McGahee is goal line, McClain will not see many opportunities)
With your team, I'd probably go with Greene though. You have enough depth to go with the upside pick rather than the definite lower production of Edge. I do like Greene better than Coffee. You could always see what the Gore owner would give you for Coffee though, but it would have been better to do before week 1.
Let me know what you think of my WW WR evaluation:
http://www.fantasyfootballcafe.com/forums/viewtopic.php?t=446297