Memorable bad coffee:
Instant coffee out of the old coffee vending machines. Choosing the "whitener" option only made it worse.
Almost all gas stations back when robusto coffee was brewed with a Brunn into a glass carafe on a burner. Arabica coffee brewed into the thermal carafes is so much better now (still not great, but it is drinkable).
The new coffee makers at gas stations now (first seen at Casey's) that supposedly grind the coffee and then brew it on the spot. They usually show three different clear reservoirs of whole beans on top. Hot, scalding, semi-coffee flavored water. Like bad instant coffee from the old days. If I see one of those now, I just skip the coffee and get a cold brew in a can or energy drink. A real step back in gas station coffee.