I've never even heard of those places. Over here, the "chaviest" place to shop is a stor called Savers. If you dress oddly people always say you shop at Savers. My mom and I don't care though. We shop there when we feel like it, which is rarely ever but still.
I had to look up chaviest on urban dictionary. From what I can muster, it either is related to being poor or rebellious.
If that's true, I guess the chaviest places would be the $0.99 store or hot topic, but hot topic is pretty mainstream.