I work around the corner from here so pop in for take-away quite often. It's cheap, cheerful & tasty. I almost always get the Pork Chipotle 'Mini-B' Burrito ($7.90) with brown rice (50c) & guacamole ($1).
I've tried the Steak Chipotle in a burrito, which was a bit tough, and the Grilled Chicken Salad ($12) which was very generous in serving, and super delicious.
The condiment bar has jalapeno peppers, fresh coriander, red onion, and three types of Tabasco, all of which you can put into tiny plastic containers for your takeaway meal. This is a truly awesome bonus.
Visit between 11am and 2pm to get a can of standard soft drink for only $1 with your meal. Their Mexican Cola is sublime but the bottled soft drinks are $4.50 each so a little overpriced.
The service can be a little patchy (I've had my guacamole left out once or twice) but the staff are always smiling and happy to rectify any mistakes.
GYG is a great addition to the Northbridge food scene as it is super fast, well-priced, and delicious.

Approximate cost: $11