My team went to the Saigon in Sunnyvale for a dim sum lunch. We waited about 15 minutes (on a monday lunchtime!) but it was worth it. The full dim sum experience with trolleys and and the raucous atmosphere of hundreds of people enjoying their food and tea.
Staff were typically rushed and slightly sullen trolley drivers, but they were helpful when it came to special requests.
It's not the best dim sum I've ever had, but for the middle is Silicon Valley it was like an oasis of tasty food. $16 a head for our group incl. tip.