Udon has recently begun to receive the type of adulation that the Japanese have traditionally reserved for soba, its slender buckwheat-flour cousin. If you don't have the time to make your own udon from scratch(see Fresh Udon and can't make it to Japan to taste it at one of that country's many udon-ya, or udon counter joints, don't lose heart. Many varieties of imported, packaged udon noodles can be bought at Japanese food stores around the United States; we found that, as a general rule, the quality of the prepackaged udon we tried increased in direct proportion to the price. Among the best-loved styles of the noodle in Japan is the sanuki udon, which is a specialty of Kagawa Prefecture and has a deliciously chewy texture; of the different brands of dried sanuki udon we tried, those from Kawata and Nishimoto Trading Company had the best balance of flavor and a pleasingly dense texture. Another style of the noodle available dried in the United States is Akita Prefecture's prized inaniwa udon, a type that becomes glossy and nearly transparent when cooked and has a firm, silky texture; we found those from Sanwa Trading Company to be particularly appealing. A number of styles of udon are classified by their appearance rather than by their region of origin. Of those available in dried form, extra-thick gokubuto udon, a popular choice for adding to long-simmered soups, is one of our favorites, especially the noodles made by Ikeda. You can also find ramen-style precooked udon, which is sold with a spice packet and, predictably, emphasizes convenience over flavor, as well as frozen, precooked udon, which is thicker and softer than dried udon and is ready in a minute or two. A relative newcomer to the packaged-udon market is a variety called hannama, or semifresh, which has an especially pliant, chewy consistency.