Great Bike Shop.
I could not afford a new bike so they helped customize an old road bike. For a lot less money than a new bike, they added a shorter stem and a different set of pedals. They had me sit on the bike and made several adjustments until it was correct. Although I hope to buy an new bike in the future, with the help of South Shore Cyclery, I should make it through this riding season just fine.
Friendly, knowledgeable staff.
I had a great experience buying a Bianchi from South Shore Cyclery. They were obviously quite knowledgeable about the bikes they carry, and were very upfront about the trade-offs between various models and price-points. I never felt like I was being given a "sales pitch" or anything. They let me test-ride various models and configurations until I found something I was comfortable with.
The amount of foot (and wheel!) traffic through the store is a testament to their growing popularity. I highly recommend visiting them.