My co-worker is from Vietnam (and a huge foodie), When I was inquire about a Banh Mi store that I wanted to try, she steered me towards a different one.
In the Peach Garden Restaurant on Jane and Sheppard (in the Price Chopper plaza) there is a Banh Mi counter that does it right.
First, all their bread is made on site, they have whole wheat and white, though I think the whole wheat is more popular as when I asked for white, they were unavailable--while they were still baking more whole wheat. The bun tends to be chewier and more french bread like than the ones I find on Spadina. Also, slightly longer.
More importantly, the filling is grilled meat, as in the meat you find on top of the bun or com dishes. The choices are chicken, pork and beef (that is also my order of preference...though all are very good). My co-worker was telling me how in Vietnam grilled meat is a very common option and how annoyed she is of the mainly cold cut options in other stores.
This Banh Mi store is a fairly new location. The restaurant use to be a donut shop or something so it already had all the baking equipment. The Banh Mi proprietor only really needed a booth and an oven, so he basically sub-let a corner of the Peach Garden restaurant to run his banh mi business. Peach garden is okay too...but the banh mis totally rock. They are $3 for grilled meat and $2.50 for your regular cold cuts. I knew about this place for a while, but was worried that if I chowhound it, it would get too busy and quality might slip. After trying the last of the 3 meats yesterday, I know it's time to share my knowledge. Enjoy.