Anything open early (5am) in Markham/Richmond Hill
It's nothing but serviceable, but Markham Station (Markham Road and Sheppard) offers up reasonably decent breakfasts. However, I'm disappointed they offer frozen potatoes as "home fries"; ask for rice or roast potatoes if you want the starch, or extra tomato slices if you don't. Open 24 hours, and if you ask really nicely, they might give you the breakfast special price of $4.99 before 6 am. A little out of the way, but just off the 401, so it shouldn't add too much travel time at that time of day.