Growing up in Ohio we had Shell and Sohio, Gulf, Mobil, Certified, Clark, Bonded and Marathon. We had a Sinclair when I was pretty small, then it became Arco, then a used car lot. We also had a Sunoco with the flashing neon arrow in the sign. That station eventually became a series of off-brand stations. There was something called Gastown that was pretty much around during the 80s. In the 80s there was also a Unocal/Union76...I think it was a different brand earlier than that. Now it's a Marathon.
Over the state line in Indiana, they had Amoco instead of Sohio. There was a Gladieaux refinery (or maybe just a tank farm) and station on the way into Fort Wayne. There was a Citgo on the way to the lake--can't remember if it was in Rome City or Wolcottville--it was one of those landmarks that as a kid told me we were finally ALMOST THERE! Some time in the mid-80s something called Futuregas opened on Coliseum Blvd in Fort Wayne--it was brightly lit, bigger than other stations at the time, and had talking gas pumps and I don't know what all. Mostly a big gimmick, I'm sure. It's long since been converted to Speedway.
I remember back in the day, my folks' Sohio card showed the 'exotic' places that also took the card--Esso, BP, Boron, and I think certain Mobil and Gulf. Off topic, their Lazarus card also listed the other department stores it could be used at (or used to open that store's charge, maybe).