Empress Pavilion is THE place for dim sum, especially on weekends (prepare to get there early or wait if you go on a Saturday or Sunday). It's cheap and delicious, and is definitely an experience. The huge room with dozens upon dozens of tables makes for great people-watching, and also lends itself well to large groups.
--Sometimes the women in charge of the carts aren't accurate or understandable when telling you what an item is
--If you're vegetarian, there's not a whole lot available
--If you want "regular" Chinese food, ask for the a la carte dishes menu. They won't give it to you automatically. This food is also terrific.
--A great place to take out-of-towners.
--I've attended a wedding reception and a birthday party there; they do great catering.