Microbreweries of Portland OR
BridgePort
Portland Brewing
Widmer
Rogue (close enough + they have a pub in PDX)
McMenamins
Lucky Labrador
Full Sail (again see Rogue comments)
Alameda
Laurelwood
Amnesia
Roots Organic
Tugboat
Hair of the Dog
New Old Lompoc
Tuck's
+ a new one is going in on NE Alberta

A couple others from around the state, which I've been to...
Pelican Pub
Bend Brewing
Deschutes

Oregon Brewers Guild
Oregon Brew Crew

there's more, its seems like every Portland neighboorhood has a brewpub, and many of the smaller towns around the state have their own brewpubs. Its exciting to try all wonderful flavors!

Beer Expedition
Real Beer
Beer Hunter