Went to check the locations since this had me curious. Unfortunately not locations here in Alberta, but really want to say I'm impressed that they use OpenStreetMap instead of Google Maps for their locations directory.
Depends what you are looking for but don’t forget London Drugs. They actually have a lot of stuff! No large appliances I think but from smaller appliances to computers, camera gear, cables and hard drives to headphones etc. If you don’t have one close by they ship Canada wide!
Sayal Electronics for your DIY electronics, DIPs and ICs, DIY A/V components, bulk cable, hobby and educational kits, kids learning toys, etc. They are headquartered in Northern Toronto and have a few locations in the GTA, and ship Canada-wide. They often beat Amazon in price for slightly more reliable components.
Gibby's Electronics Supermarket in St Catharines has more home theater equipment than computer parts, but they have a great selection and you generally won't beat their prices anywhere else, and they ship.
https://www.circuittest.com/ - Burnaby-based brand of power supplies, etc. Not made in Canada, but they test them for CSA/UL here and distribute them under their own brand.