I've had two different kinds of really good dealers.

The all business guy. Gives you exact prices, weighs it out in front of you, gives you the exact amount no less, thanks you and leaves.
and
The really friendly dealer. The kind who sells only so he can smoke tons. This guy smokes you out everytime you buy from him and gives generous baggies. I'm kind of a sociophobe so this kind always makes me nervous, but they're way cool.