This one is cheapest from PDX to BNA (via ATL) but does work via LAX and from BNA to PDX for a little higher CPM. Still not a bad run but it does require and overnight.
5,344MQMs via ATL & 4.6cpm
Bookable on Delta.com
DM yields is a nice 12,0248 Skymiles per CWSI.net, PM & GM 10,688 and FO 6,680