My go to LBS is a big Trek store. The team is great and give awesome attention to the many vintage rides I bring in to them. I cannot say enough good things about The Bike Shoppe in Ogden, UT. Yep, free plug. They are awesome.
Oh and to be honest I don't own any Treks. They probably do about 50% of the work on my vintage bikes which is a lot with over 20 bikes. I'd rather ride than work on the bikes so I give them a lot of business. Even the younger group seems to really like messing with my old stuff.