For your amusement - or as an argument stopper, or starter - the National Review rundown of "liberal" and "conservative" rankings for all the members of Congress.
Readers of this site will recall our frequent argument that both terms of political philosophy have been so twisted and abused by the politics of the last generation that both are meaningless as a practical matter. As a loose descriptor of where these members fit into the policy picture, though, it's worth a look (and maybe as a case in point of our point). These are, we should note, reviews of 2006 voting; this year's activity isn't factored in.
Northwest overall, on the liberal side, the highest numbers went to Washington Representative Jim McDermott, with second place to Senator Patty Murray. Top conservative numbers regionally went to - you were expecting Idaho to show up here, right? - Washington Representatives Cathy McMorris and Doc Hastings, respectively. All of the Oregon and Idaho members ranked in between.
All depends on how you count.