What about tea?

Pouring tea
Originally uploaded by KaiChanVong

When you visit a more formal dim sum or Chinese restaurant, you'll be asked for which tea you'd like to be served.

Some of the more traditional places may serve:

Pu-erh (or Bo-Lay) - red tea made from a "large leaf" variety of the tea plant and named after Pu'er county in China. It has mellow or "earthy" taste.

Tie Guan Yin or "iron Buddha" - is a premium variety of Chinese oolong tea (see also below) associated with Anxi, which is in the Fujian province in China. It has an orchid fragrance and heavy yet pure aroma. If it's served in a small and exquisite tea set, by smelling it first and then tasting it, you will have endless aftertaste in your mouth.

If you get a funny look, just ask for one of these:

Oolong - a traditional Chinese tea which is commonly brewed to be strong with a slight bitterness and at the same time having a sweet aftertaste.

Jasmine - tea made from Green or Pouchong tea leaves that are scented with jasmine flowers

Chrysanthemum - tea made from Chrysanthemum flowers having a soft to bright yellow in color and a floral aroma.

Chrysanthemum tea
Originally uploaded by **Shutterbug Gal**

My favorite is probably the Oolong. Its rich flavor nicely offers a nice cleansing balance when enjoying heavier dim sum dishes.

One important thing, when you run out of tea, be sure to open up the tea kettle cap and leave it tilted so the waiter/waitress knows you need a refill.

Sources: Wikipedia and ChinaCulture.org