We ate here when visiting Toronto, and let me tell you these tacos are some of the BEST I have ever had.
We went here on a Sunday and Kensington Market was packed. The food, however, is worth the wait (15 minutes).
The dining area inside is tiny, so you can either get your food to go, or do some people watching at the counters that face outside.
Some recommendations:
Baja Fish Tacos!
Mahi Tacos
Pork Tacos
They only accept CASH so be prepared! Expect to pay $4-$5 per taco. They are stuffed and very filling and are worth the $$ you pay. Kensington Market is wonderful, and food places like Seven Lives are a big reason why.