For manga I usually go to Borders...they have anime DVDs there, too.
The Suncoast that closed here - Oh, I miss it. It was a DVD and Pocky heaven xD
There are two Borders in Salem, by the way - Borders Express in Salem Center and one on Lancaster, the latter being much bigger and a little more organized.
...And you can preorder manga there. I did it with MeruPuri. =]
Edit - How did I forget Uwajimaya/Kinokuniya in Beaverton? D:
They have manga in Japanese, too.