Big Fat Burrito makes one of the better burritos I've had in the city. I've never been blown away by a burrito here but they're consistently good.
I usually go for a large yam burrito which, at $8.50, is a little expensive. Despite the name of the place, the burritos here aren't massive; I'm comfortably full but not stuffed after eating one. On my most recent visit I was also impressed by how well my burrito stayed together.
The yam is delicious and really makes these burritos stand out. The other toppings (rice, beans, guac, veg, etc.) are above average by Toronto burrito standards but just seemed to be missing a little something. Perhaps a better burrito sauce or salsa would help with this. Also, I ordered mine spicy and didn't taste any heat.
Four stars for the delicious yam and I'd up it to 5 if they perfected the rest of the toppings.
Pro Tip: On my most recent visit my friend ordered a pulled pork AND yam burrito. I didn't know you could combine fillings like this but it sounded like an amazing combo. With 7 possible fillings this means there are a total of 7 + 7*6 = 49 possible unique burritos. So get out there are start experimenting.