I agree with you folks. There are two shops I frequent the most.
The owner of one of them is very well known in the profession and he is always pleasant and very friendly. I sometimes call on a Sunday to see if he is in town and even if he is not officially 'open', he invites me to stop in and visit. While it is true that I have been buying coins from him for a couple of years, my purchases are always on the small side - maybe $20-$50. He is well aware of my "comfort level" and he never pushes it except in a very friendly way..... I am most impressed by his willingness to provide his expert opinion and to explain things to me. Here's a true example...I purchased a 1921 Peace Dollar a while ago and not from him - it was part of a lot with a number of other coins and I would say that I got a pretty good deal (although as some noted here when I posted it, that it has been cleaned mildly - something I could see right away). There was a small die crack, which in itself was no big deal, but it was on the rim and I wasn't too familiar with that. On one visit, I brought the coin to him and he examined it, told me what he thought the grade was (which was higher than what I thought) and when I asked him about the 'crack' he said - yes that is a die problem and it is not unusual and that you can see this on other 1921s and to various degrees. He then took me through all of his 1921s to show me...and sure enough, there it was on some others.
The second shop I frequent is very different. This fellow has probably the greatest amount of US stock that I have ever seen. He seems to do a huge buisness in bullion and sells to other dealers all the time. Consequently, his shop can be overflowing on a Saturday and I might have to wait 30 min to get to see a 1938 Jefferson and get the price. But he is fair and there is no haggling - if you don't want to buy it, that's fine and he doesn't hold it against you at all. Thing is, if you can get to him when he is not swamped, he is a freaking gold mine of information and he is happy to shoot the breeze with you.
Those are the qualities I like most - honesty, respect for the customer, expertise, friendliness.