I just... don't!!
Most of them smell, get their hairs everywhere, dribble on you, their breath makes me heave, they beg for food and get their food/water everywhere when they eat. They're expensive and needy and annoying.
But why do people get so angry when others don't like dogs? I feel like I can't be honest about dogs when I meet them and their owners, and I always end up pretending to like them. God forbid you say to a dog owners face you don't like dogs, you might aswell just say you've killed a baby!