Though it is not in Portland, I would like to add Sesame Donuts to this list.
I went there Sunday night and saw their donut holes for the 1st time. They have 7 varieties and are only 15¢ each. FIFTEEN CENTS!!! 15 of them were $1.75! Sesame donuts are very tasty. And addictive. (Next time I will buy 30. Or 60)