Not a comic shop, but a company.
I found out about Top Shelf when they were in financial straits a few years back. I wanted to do what I could to help, so I called up and placed a large order of a few books I'd had my eye on. The owner was actually manning the phone and took my order. He was helpful and polite, and even made several excellent suggestions. The package arrived swiftly and full of extra swag. Simply a great company.