Basic has had a store in Southland Mall for about as long as I can remember. They carry very inexpensive, trendy clothes which are geared towards a teenage clientele.
All of the clothes are made cheaply in foreign countries, and they don't carry any big or designer labels. Quality is usually pretty low, but for a trendy piece you might only wear a few times before it is out of style, it's easy to justify buying. You just have to dig to find stuff that looks good, and isn't too poorly constructed. I've bought a few fun items here and there over the years, and most usually last just fine through the season.
Sizes tend to run small. If you're a bigger/curvier girl, you may want to check out their newer store, Basic II, which is right next door. They carry many of the same styles in larger sizes.