I think it's an individual thing to be honest. For example, my JRT/Yorkie cross is super affectionate with people. She just adores people and will go out of her way to receive attention. But yet she hates other dogs.
Both my boys are deeply affectionate with myself and family, but aloof with random strangers, so depends on what you're looking for really. A friendly dog with everyone and everything? Or content to just be affectionate with close family and friends? If the latter, most dogs fit that requirement IMO.