I agree with all these posts. cheap, colorful, huge menu, good horchata, tres leches cake at the panaderia....
Not much more has to be emphasized, however, one reccommendation: get the ELOTE along with whatever you decide to get. Its corn on a stick covered in mayo and queso- delicioso. if you really want a treat, squirt ketchup all over it too. mmmm market foooood