When it comes to brands and gasoline you don't always get what you think you are getting. In the NJ/PA area there are 4 major refineries that serve every single has station for quite a large radius. When the Sunoco plant for example is shut down for maintenance/upgrades the other plants supply their fuel needs and vise versa. There are also stations that don't have local refineries in our area such as BP or Gulf, they get their fuel from the local available refineries as well.
Personally I go to stations that I trust and have used for years, when on the road traveling it is what it is and I go wherever I have to to get fuel. I typically like to use stations that are well maintained, first impressions I guess lol. In NJ the Dept of Consumer Affairs has a list of stations served infractions for fuel not meeting posted standards, I avoid these stations completely...