Personally, I prefer ARCO. The quality of their gas sucks but they have the cheapest gas around. Besides, I have friends who work for the parent, BP Amoco.
How can the gas quality suck? All gas comes out of the same pipelines into the trucks that take it to the stations.
Any differentiation in the fuels is done in the trucks. Are you saying that they don't do as much cool stuff to the gas as other people?