I don't go to BP either, but they aren't any cheaper than the other places around here. There are a few automotive repair businesses I avoid from bad past experiences.
I try to avoid Walmart but convenience gets to me sometimes.
Edit: Also I can't remember which bank it is now, but I try to avoid the really big banks because they always seem to dick you around. Lastly, my girlfriend had bought furniture and was paying monthly and the place always messed up the payments, charging more, and repeatedly did it. I can't remember the name but I'm sure she will never forget how annoying it was.