Amma, which is at the end of my street, has changed hands several times in the 10 years I've lived here. It's now back under one of the first managers, and the food quality is back up to where it should be.
First off, a warning: you have to like aggressively spicy Sri Lankan flavours to eat here. While there are a few more delicately flavoured dishes, pretty much all of the curries are laden with green chili. The standby is kothu roti, a filling dish of fried egg, onions, chili and curry, all mixed in with chopped flatbread (roti). A giant container of this is only $6, and feeds more than two people.
The biryanis are great and fresh, and the plain roti are exquisite. The place is busy every evening. While the decor is a little rough, and there's nowhere to sit, the food is amazing, and the owner very friendly. I'm so glad that this place is only three minutes' walk from my house.