I've been going to Chef Chan for over 15 years and it is definitely my favourite Chinese food restaurant. The food is consistently good and in 15 years I think they've only gotten my order wrong in 1 or 2 occasions.
Their dinner for 1 combos are also very good value ($7 for fried rice, an egg roll, and a can of pop, and your choice of breaded shrimp, chicken balls, and a few others).
I used to live in Markham but moved to Stouffville. I try to grab some Chef Chan whenever I'm in the area and sometimes find excuses to drive down.