This tiny place has been here since 1931. I think these are by far the BEST donuts in Boston.
There's only a few items in the mostly empty store: plain donuts, filled donuts, cruellers, cookies and pastries. They tend to have random hours (closed Mondays and only open in the mornings until around 10am), so don't always count on them being open, but 30 cents for a great donut is hard to beat. They're out the door as quickly as they make them, hot fried amber bits of heaven. Also, if you're ever there on a Sat. morning, get the baked beans. They cook them in their coal-fueled oven.