I don't know how long you are going to be in PDX for, but my favorite restaurant is Veritable Quandary (http://www.veritablequandary.com).
The seafood stew is excellent and they have a great wine list (Patricia Green is always good).
Adina is also good. (http://www.andinarestaurant.com)
I think you need to make reservations for both of the above.
Rock Bottom (http://www.rockbottom.com) is pretty good for casual dining. Good food and beer.
If you like chocolate, you have to make it to Moonstruck (http://www.moonstruckchocolate.com.)
Voodoo Donuts are evil.