There are a lot of things to see in Oregon. If ou have the time to drive. here is a link to a site that you might enjoy. Explore Oregon - Travel Oregon
Me personaly I enjoyed the Painted Hills, Crater Lake, and the lava beds the best.
I guess that would depend on what you want to see, Oregon has the deepest lake in North America, it also has the deepest canyon in the Northern Hemisphere, it also has the largest geological fault in North America. These are just a few things to see, also allot of the towns in Oregon are worth seeing due to their historical value.
I travel to the Portland,OR area often, If I got xfer'd with Yahoo! to the Washington datacenter they have I'll take it in a heartbeat!
You have the mountains and the coast line. If you have time, just driving along the 101 and going through the various beach and sea towns is just a blast!
Also, hit up voodoo donuts while your in downport portland. They are the freaking bomb!