The taqueria in back of the market is one of my favorite spots in Madison.
The burritos have recently become a bit smaller than they used to be but the quality is as good as ever, (ask for asada & chorizo with everything on it and you wont be disappointed). They have an amazing verde salsa with some great heat but if you eat there make sure to grab a bottle of the verde mixed with guacamole they have sitting on the tables.
On Sundays they make a bunch of specialty items; the tamales are fantastic.