The ones that stood out to me were when i was the customer.
One of the best: My car dealer took the time to understand an issue I was having and why it was important to get it addressed. When it was time to check out, the rep went over my issue and how they fixed it and took the time to check out other things that could go wrong during my trip and address those as well. Explaining why they did the extra services (which i gladly paid for)
One of the worst was my internet (former) provider: I called with an need for more speed (who doesnt have that) 30 minutes on hold (with “sales” messages laying every 60 seconds), a live person who needed to connect me elsewhere (without questions to determine the issue) and a disconnected line, I switched.