Some companies have brand image as being "audiophile/ videophile". From a business perspective, it will be good to have some of these on display (if you have a walk in establishment). Just the name, looks, price tag, and the fact that you carry them will make customers believe that you have authority in the business. But you must also carry brands that your Average 9am-5pm Joe with a hobby can afford. Just being able to say that you can install a setup for all budgets will increase business. Then again, you already knew that.
These based on reviews I have read or products I have drooled over: Lexicon, Krell, Thule, Anthem
For your Average 9to5 Joe (like me): Denon, Marantz, Yamaha, H/K, Onkyo, Sony, Pioneer.