In Berkeley my favorite eatin' place is now Cancun, at 2134 Allston Way.
Why? The pumpkin seed sauce. They have a whole salad bar full of sauces. Ignore the other eleven. Fill every one of your alloted sauce bowls with pumpkin seed. It's got a smoky taste balanced just right with a burn underneath. It's a complex taste somehow and changes depending on your combination of meat, veggies and rice of the burrito mouthful to mouthful.
Ignore the artsy selections on the menu and get a simple buritto with pork. Slather it in the pumpkin sauce. Heaven.
The #4 (or is it #7 ?), which is a chocolate mole dish, is also fine and worth checking out for occasional variety. Avoid the fruit drinks. Stingy portions will not last through a meal, while the self-serve soda will.