Best tacos in Toronto in my opinion, (my baseline is Playa Cabana) however there is minimal to non-existent seating so it's a stand and eat or takeout type of joint. Standing and eating takes some extreme skill though as you'll probably get sauce all over yourself if you're a newb.
My favorite is the octopus although every taco is delicious in a different way. Don't forget the 3 hot sauces (hot, med, mild) as that gives some great kick as well. Like most popular places I would suggest going on off hours to try to grab a seat and avoid lineups.