When I can't wait for online delivery from Newegg, Canada Computers (CC) is the place I hit when I need something computer related. Skip the big box stores and their inflated prices for computer components and support the smaller stores (although I guess CC doesn't count as small anymore with their 15+ locations in Ontario).
Anyhow, CC in Mississauga moved from their tiny location on Mavis/Eglinton to this massive location. I visited here to pick up a card reader and though how the heck could they fill this store with merchandise? It's gigantic! There are a tons of demo laptops, TVs, computer cases on display. If you're after a smaller item, it will save you a lot of time if you ask someone where to find it as the aisle labelling isn't the clearest.
Their pricing is competitive although usually slightly higher than online which is to be expected. But if you need something now, the small premium is generally worth it.
They also stock Mac upgrades, so instead of paying Apple's exorbitant ram or hard drive prices, save some money, do it yourself, or have one of their techs do it!