Ah, I got a great laugh out of reading your responses. I am a fellow grocery store junkie born and bred in Toronto.
What can't you easily find in Canada is ROTEL (I know, but its just not here) Hominy ( to make posele), Various Lousiana or Creole ingredients but you can find it all in specialty shops in the city. Cleaning wise, very hard to get 'Bartenders Friend'. And sadly, "Payday Bars and Sugar Babies" are not Canadian friendly.
My favorite grocery stores in the world are in France! I have dragged the husband through many.
You mentioned you were a vegetarian, did you happen to go up to Harbord St to Kensignton Kitchen? Very good Vegetarian. Or did you try the Vegetarian 'Lick's Burger' while you were here?
Ah so next visit, you will have to try "The Cheese Boutique" on Ripley Ave in the west end. If you like groceries, you will have thought you hit the motherload! First of all Killer Cheese is the main star here, but, the perimeter walls are stacked to the ceiling with groceries from around the world. Not cheap but damm impressive and you can stay for lunch at the restaurant/cafe. For strange but true, Boncheff's Greenhouses off Kipling has a large section of gourmet foods and as they are a greenhouse primarily they specialize in edible flowers and minature vegetables. Too much fun.

Now I have some more ideas for when we return to Toronto! We found that there is a LOT of "Oh Henry" candy available in Canada that we had not seen in the states... interesting.

I miss the pear juices and yogurts that are so plentiful in Europe (and Asia, and Central America...) in the US. I bought 2 containers of pear juice in Fortino's... yum!