Depending on the service/repair you are needing. You should apply the same logic to making a selection for this as you would making any purchase. Reputation, reliability, workmanship, licensing, availability, durability, insurability, etc. Once you have chosen a company to work with, then you should be loyal to them. If they provide you with good honest service, then they have earned the opportunity to continue doing that service. Ask neighbors, friends, co-workers for recommendations if you don't know who to call. I would advise AGAINST making a choice simply from the yellow pages.