I like Empire Court in Markham for dim sum.
Most of my go-tos are in Richmond Hill, but these ones are a short drive from Markham: Ambassador for dim sum, John's BBQ for the special order King of Char Siu , Northern Dumpling Kitchen for dumplings, Ruelo for macarons and other desserts.
Check out this amazing thread: http://chowhound.chow.com/topics/703979 . There's also a search function, in the top right corner of your screen, where you can search Markham and any other search term that might help narrow your search.
Also might want to read this recent thread about Fisherman Clubhouse, a Chinese seafood restaurant in Markham: http://chowhound.chow.com/topics/823553
280 W Beaver Creek Rd, Richmond Hill, ON L4B, CA
550 Hwy 7 E, Richmond Hill, ON L4B, CA
Northern Dumpling Kitchen
550 7 Hwy E, Richmond Hill, ON L4B3Z4, CA
Literally across the street from Markham, but technically still in Scarborough, the Fisherman Clubhouse has excellent Cantonese dishes, especially seafood. If you find the parking in that little mall too overwhelming, a fine dining Cantonese alternative is Casa Imperial, a few blocks west on Steeles....also in Scarborough, with Markham across the street.
Spring Villa for dim sum is quite good and classy
7301 Woodbine Ave.
Jim Chi Kee, it is a hole in the wall but the wonton noodle soup or the fish ball noodle soup are great. The wontons are the biggest I've ever seen and very fresh.
270 West Beaver Creek
If you want to try a bit of this and that, First Markham place has a interesting selection in their food court. There's also many, many food options in the plaza. I like Din Tai Fung Shanghai dim sum and Tracy Dessert for chinese-style puddings.
3255 Hwy 7 East
Instead of Jim Chi Kee, I would recommend 'Wonton Hut' in the plaza, SW corner of Hwy#7 and Warden ( same plaza as Casa Victoria ). Better tasting broth, better/finer strand noodles, condiments of yellowing chives and dried shrimp eggs and tastier won-tons ( although both places do not offer 'genuine' wonton but a 'mutated golf ball size version'. Authentic Hong Kong style won-ton should be 'single bite-size' morsel as the name implies and preferably consist of one single whole prawns! BTW, atmosphere of WonTon Hut is much better! In the case of Cantonese won-ton. Bigger does NOT equate to better!! Same applies to nigiri sushi!
See my posting on this subject:http://chowhound.chow.com/topics/399024
Speaking of Casa Victoria, one of the best Chinese fine dining establishment in the area, though a bit on the expensive side! Worth a try!