Quick, cheap and utterly DELICIOUS.
I regularly visit Fiesta Burrito to curb my desire for (you guessed it) a big ol' burrito. You can get a huge plate of tasty Mexican food here for only a few dollars. And your food is usually ready in less than three minutes. I'm being serious. This place is gold.
Try their chimichanga plate or the rolled tacos with guacamole, and order a "pina" drink to go along with it. It's great for lunch, dinner or midnight snacking.