Since this thread began, the changes at CO would move them to the cellar with DL.

If you are flying on economy fares and some of that travel is to Europe, the third worst would be AA because of the way they shortchange economy ticket travellers on miles with flights on their partners.

My order would be:
NW
UA
US
AA
CO/DL (tie for worst)

This list would apply to mixed fare travellers as well as low yield travellers.

[This message has been edited by Carolinian (edited Jan 11, 2004).]