You's is good, and actually has several locations in Chinatown, one on Grant Avenue between Sacramento and Washington, and a nother on Washington at Ross.
Another good cheep dim sum option is Louie's on Stockton at Broadway. Best hargow and pork buns in the city! Take out only.
More upscale dim sum at City View restaurant on Commerical at Kearny.
Other good Chinese food
R&G Lounge on Kearny at Sacramento, good chinese food less spicy, kinder to the tastebuds than the Hunan and Scheshwan food.
Yuet Lee - bare bones Chinese served until 2am. The calimari is amazing.
Henry’s Hunan at 674 Sacramento, on Battery at Broadway or between 2nd and New Montgomery and Harrison and Folsom south of Market near the MOMA. - Great Chinese don’t miss Diana’s Meat Pie.
And outside Chinatown
Tai Chi on Polk at Broadway has the best General's Tso's Chicken just the right combo of sweet, hot and garlic. They also do really good shrimp won ton soup and sizzling beef and scallops.