Try a Burritozilla, which is 5lbs of burrito for $18.75, recently featured on Man v. Food and other shows. Their regular burritos are $3.50 and tacos are $2.50, open late. Read more.
Make your own ice cream sando with whatever combo you desire- $3 or $2.50 if you pay cash. Excellent late night snack- they're open until 2! Expect a wait.
Love their drinks! Can't get a reservation? Still hungry late night? Come after 10pm on the weekends for their "happy hour" menu! Get a roasted bone marrow or a burger and some drinks!