http://vettenet.org/octane.html
This link has some great info about gasoline and its additives, and makes note of the fact that companies trade base gasoline all the time. It doesnt become your brand of choice until the additives are put in. By the time the gas gets to the station its nearly impossible to tell where the oil originated from, making it impossible to say you wont use a company because they use so-and-so's oil.
That said, I normally fill up on chevron since its a top tier fuel and right around the corner from my house. Away from home, any top tier brand will do.