for clothes I mostly buy from wet seal and Lauren Conrad collection. Also a little from target since I work their. But when it comes to jeans I prefer designer so I stick with J Brand and Paige with the occasional american eagle jean.
Thrift shops,Walmart, Internets, Hot Topic, Hot Rags(I don't know if that's a thing outside of the mall I go to), I also sometimes get fancy stuff on ioffer.com for really cheap.
For me, usually second-hand clothing stores have the best quality clothes. My favorite is Value Village. I can honestly say their clothes rival the likes of YSL & Prada in terms of fashion. Sometimes at night when all the thrift shops are closed, I just go digging through the charity bins at my local Catholic church. It's amazing what people will give away.
Topman, American Apparel, General Pants Co. and Glue. Those are the main four in Australia that fit my taste. Plus, sometimes I find other nice clothes from independent brand-only retailers in the city. When I was in the States, I bought a lot from Urban Outfitters and H&M though. They need to open some stores down here. There is demand.