Macys. On sale, generally some sort of coupon from the paper/flyer. I've bought fancy dresses for less than $10. Shirts, jeans you name it. Look only at the sale racks and ask the cashier if there are any additional discounts. Great quality, great prices.
Aeropostale has great sales, too. Sign up for their emails and you will get advance notice. I bought jeans, t shirts, sweats etc...nothing over $15 or so.