Very tasty, inexpensive ($2.25) subs at Dundas/Spadina. If you have a TTC pass and are by the area, worth jumping off to grab one, or if you're super hungry, two. To second Susan's rec: try the BBQ Pork Banh Mi (get it spicy).
I'll give it four stars strictly as a sub takeout (you will not want to stick around).
ETA - ask them not to put on too much mayo if its not your thing, there was quite a bit on mine...