I don’t personally know of any great standalone delis, but I’m sure they exist. There are probably some in the Jewish section of North York. I no longer live in the city anyway.
But if someone were to ask me for a great deli suggestion, I would point them to the inimitable Pusateri’s. I have no idea where they get their deli items, but they have tons of stuff you won’t find anywhere else, along with a superb meat counter, and a fish shop that features the best smoked salmon I’ve ever had in my life!