To the unknowing passerby, the House of Nanking has "greasy dive" written all over it. To its legion of fans, however, the wait -- sometimes up to an hour -- is worth what's on the plate. At the edge of Chinatown, just off Columbus Avenue, this inconspicuous little diner is one of San Francisco's worst-kept secrets. Still, if you want to know what the fuss is about, drop by and order a plate of pot stickers and chef-owner Peter Fang's signature shrimp-and-green-onion pancake, served with peanut sauce. You can select from a good number of pork, rice, beef, seafood, chicken, or vegetable dishes, but I suggest you trust the waiter when he recommends a special, or simply point to what looks good on someone else's table. Even with an expansion that doubled the space, seating is tight, so prepare to be bumped around a bit and don't expect good service -- it's all part of the Nanking experience.