Hong Kong Market has one of the best selections of East Asian produce in the DFW area. The large grocery also has a meat/fish market and aisles and aisles of packaged products, most of them Chinese but also from Japan, Korea, and other countries. There is a media area at the front of the supermarket, selling Asian movies and music. If you enter the right entrance of the building, you'll find yourself in an area immediately adjacent to the supermarket that has some restaurants selling quick meals, as well as a bakery. There's also a mini-shop selling Japanese, Korean, and Chinese character goods, including the much-coveted Tarepanda plushies.
Some of the products they sell in the supermarket-proper are expired, so beware of buying packaged products. They are highly recommended though for their selection of fresh foods.