I have had dim sum in San Francisco, D.C., and elsewhere, and think that Shanghai Chinese & Dim Sum in Austin is among the best. Their variety is good and quality is very good. Go there either at 11 a.m. on Saturday or Sunday (opening time), or 1:30 or so. In other words, the closer to noon, the more likely it is to have a crowd, and early afternoons are when their variety is best. Prices are moderate.