The best service I ever had was with a server who could either read people very well, or was not very good at their job! Haha, that makes no sense, but I'll explain:
I like to be left alone at a restaurant. I like to eat my food and leave. I don't like small talk, especially with strangers, and I'm not huge on dinner conversation in restaurants - I have social anxiety issues and prefer to have my conversations in private places.
We had a waiter who was polite, but not overly friendly, did not make small talk, and was very efficient. He took our orders, refilled our drinks and brought extra napkins with the food (so we didn't have to ask), left us to eat for a few minutes, and brought our check. No nonsense. I loved it. I left a $20 tip (probably 80%). I never saw him again. I told this story to my sister, who has a lot of serving experience, and she said most people would find him to be an awful waiter. He made no attempt to be "friendly," converse with us, and many people would have complained about his "attitude." I hope he was just able to read us well instead of treating everyone like that.