1) Audio Spectrum, in the Altamonte Mall in Florida -- mid to late 70's. That's where I drooled over the most equipment in grade school and high school. They carried a lot of high-end equipment I could not afford, but as a 13-ish year old, the salespeople would still take the time time to demo everything for me as if I could afford it. When I finally scraped up the money, I did buy Advents and a Nakamich BX-2 cassette deck from them, which were the least expensive items they carried. I had my eye on Yamaha receivers -- which were very expensive (relative to Pioneer, Marantz, etc.) back then when new (but ironically are somewhat under valued in today's hot vintage market). I couldn't swing the Yamaha, and had to go to different store (name escapes me) in the Colonial Mall to buy a receiver I could afford (Superscope 10wpc).
2) The Salt Lick in Driftwood, TX, today. I would just sit down at the table with my family and never leave.