Zapatista is still around, and churning out sometimes good/sometimes just ok food. It's not in the 'hood so much, but Pancho Pistolas in Bridgeport is good and they will deliver to the South Loop.
Pancho Pistolas
700 West 31st
Chicago, IL 60616
(312) 225-8808
I will eventually get around to posting a separate thread about this place because I love it so much, but another great place you must check out is Pannozzo's Italian Market on South Michigan (1 door south of 13th Street.) They have great carry out italian sandwiches and pasta, as well as lots of specialty italian items.
The South Loop is definitely flush with breakfast and lunch places, including the Bongo Room (Wabash and Roosevelt), Yolk (South Michigan just north of Roosevelt), Grace O'Malley's, Orange (Harrison in Printers Row), and even Gioco and Zapatista.