Numerous places. Let's see there's CPUsed on dupont and bathurst downtown. Click on macs on Eastern past broadview in the east. Red Tag in mississauga. Carbon on queen in the east end. Computer systems on college and spadina. dpi on browns line I think. Canadian computer in Oakville to name a few. Then there's simmplymacs.com and macdoc is great. Just call him and you'll see what we all mean.
I really like the guys at Canadian Computer in Oakville. They happen to be in the same plaza as my store, so maybe I'm biased! But they are very knowledgeable, have great service and best of all : free parking! Call me a suburbanite, but I can't stand trying to park downtown TO anymore.
Run, don't walk to Carbon Computing in Toronto. Great Apple Authorized dealer that is official sponsor of ehMac.ca. Staff is full of Mac experts, have a really large showroom with all current Mac products in stock, tons of software and books. Great service department too.
If you want to kick tires and browse aisles, Carbon is the best show in town. Then, CPUsed, Computer Systems Centre, and Red Tag.
MacDoc puts together good refurbed packages, sells new and he knows his stuff. But he works out of his house. I'm not saying that's a bad thing, or anything; he's just not a typical "Retail Outlet" type of place. That's all. Heck, kick tires at the big places, then call MacDoc for comparitive prices.