Here are some excellent places that I have never had any problem with.
Downtown Camera, located on Queen Street about a block west of Church Street. They have a lot of harder to find items in stock, and often are several hundred dollars cheaper on the more expensive gear than Henry's and Vistek.
Henry's - All across Ontario (Plus some in Manitoba and Nova Scotia). I cannot say anything bad about Henry's, very friendly personal service, especally if you frequent a store often, they'll begin to call you by your own name. Perfect for film processing (they do a great job on Slide and B/W stuff). In fact all but two items in my arsenal were all purchased through Henry's. Henry's has an amazing selection of used equipment and very easy to deal with when trading in old gear.
Vistek - Very few stores, mostly Ontario and one in Manitoba. High End stuff here, amazing selection of lighting equipment. Also more selection in the way of photographic display items (portfolios, frames, ect). A little more expensive than Henry's, but a wider range of the higher end products. Defiantly aimed at the Pros.