Authentic or Tourst Chinese?
It depends on what you want. If you want "tourist" Chinese, where most of the patrons are not chinese and the food is made more for a western palate, then go to:
House of Nanking,
Brandy Ho's,
Tommy Toy's
If you want true authentic chinese, where most of the patrons are chinese and you're getting truly authentic chinese-style food, then go to:
R & G Lounge
Mayflower
Hong Kong Lounge in SF
Hong Kong Flower Lounge in Millbrae
Yank Sing is very good, and it is fairly authentic. However, it's incredibly expensive, and not worth the money. But Yank Sing is a good "hybrid" place. It's quite authentic, but it caters to a Western palate. It's not a total tourist trap, but in my book, I'd consider it a "rip-off" because of the exorbitant prices.
Koi palace is great for dim sum, but the line can be 2 hours or more. Besides dim sum, Koi palace is not known for the rest of its food. You can virtually just walk in anytime to eat there as long as it's not dim sum.