Rose Gardens, Washington Park Zoo (Great if you haven't been there in a few years.), NW 23rd, Multnoma Falls, Mt Tabor, OMSI.
If you like beer- McMenamins Kennedy School, BridgePort Brew Pub, Widmer Brothers, Rock Bottom
There's also an abundance of dancing clubs of the x rated veriety. I believe about 30 in the local area.
If it were me, I would probably go to OMSI and look around and catch a flik at the Omnimax. Nothing like 80+ft dome screen with something like 200 speakers all around you.
Then I would go down to Rock Bottom and get drunk.