Gilbert is not known for its Mexican.
I live close by and to discover Lulu's just down the street made my day. Its good short-order Mexican food, which is hard to find in Gilbert. The carne asada tacos are good, as are the bean and cheese burritos. I also recommend the zopes with machaca. Their salsa is chock-full of garlic, which I enjoy (for hours after the meal, in fact). They also have a number of good-looking seafood dishes that I havent gotten around to sampling.