There is a store called "Games for less" at Centro Maya. They have a fairly good selection of PS3 games. Unfortunately it takes quite some time for the newer games to come here..
However, I'm placing an order for some games from the States within a week, PM me with the games you are looking for if you are interested in adding to that order. Even with the shipping costs (around 100 pesos) it's way cheaper then the prices here.
For the food I would also check out DAC.