The shop that looks great and has nice friendly personell (they even know your name). However, in the end you want to have a shop that actually fixes your bike. I bought my expensive Trek bike (domane Slr7) here. In the past 2,5 years I've had to go there numerous times because something was wrong with the bike and unfortunately the bike usually came back with more problems than when I brought it. I always had to go back at least one more time. No wonder their workshop is so busy (minimum of 3 weeks to get your bike fixed). In the end friendliness cannot make up for bad workmanship.
Tip! When you pick up your bike there, reserve some minutes to do a test drive, most likely you can bring it back immediately for more fixes.