I grew up in the El Sereno area, and as far as I can remember, El Aguila has been thee bakery for the locals. There has been other bakeries who have tried to make their mark, but they have come and gone. El Aguila, which has recently received needed remodeling is the place to go for Pan Mexicano. Their bread is very original and so delicous with your side of coffee or chocolate caliente. They also make menudo on the weekends (bring your own casuela) $10 dollars feeds a family of 4-6, and it's so yummy. I recommend this bakery to anyone who loves Mexican pan dulce. They have it all, my favorite are the conchas and palmeras.
Pros: Best Mexican Bread in the area
Cons: Long lines on the weekends, especially early in the morning.