Kuni Sushi Ya is a great place on Baldwin Street to have cheap all you can eat sushi for lunch. Although I haven't tried the dinner menu, I would definitely recommend it for an all you can eat sushi lunch in Toronto, as the food is pretty good and the price is very reasonable for all you can eat, at $14.00 per person.
The service at the place is good and fast, and they provide both outdoors and indoor seating. In regards to the rolls themselves, I have had better spicy salmon rolls elsewhere (along with many of the fish rolls), however, they are still adequate and good for the price you are paying for all you can eat.