Dollarama is a reliable place to pick up those little household items that you would pay through the nose for at Shoppers, Canadian Tire etc. I can always find what I need here (after some searching as they seem to change the layout quite a lot).
The lineups are always long but they move fast. It seems that they have recently updated their registers as you can now pay by debit (not sure about credit). Don't even think about trying to return anything as all products are final sale.
I find Dollarama great for things like light bulbs, hand soaps, cleaning products etc., but to be honest I probably wouldn't by perishable foods here.