As a Portlander, Oregon Pizza is a topic close to my heart.
Apizza Scholls is at the very top of my list.
Nostrana is very very good wood fired oven pizza, but it is in the pricy range.
Escape From New York (on 23rd, or Trendy Third) was the best in Portland until Apizza Scholls raised the bar. I am still very fond of the place and it's atmosphere and politics, pizzaiolos(?) etc. and you never have to wait very long for a slice or two. Getting into Apizza or Nostrana on the otherhand is a game of strategy.
Hot Lips is not bad. Pizza Schmizza - curiously I've never had a bad experience at their hole in the wall store on the side of the Fox Tower, whereas the experience at every one of their other shops was uniformly bad.
Ken's Artisan has been on my wish list for a while, and it looks as though we may get there this next week.
I've read good things about the Apizza north of Salem (?). It's going on the wish list.