I've always been the type who tips based on service. But I was reading an article about tipping at nice restaurants, where dinner is $300+, and it said that even with great service, 20% tipping should be rare, because you expect good service. Sometimes, I've been to places where they've actually secretly washed my car, or I've asked the waiter for coffee to go after my meal, and he runs across the street to get the coffee...I've only been going to nice places recently, but it seems to me less than 20% would be bad. So are we suppose to tip based on expectations or service?