In Portland, make sure to visit Powell's books (one of a kind IMO) and make fun of how bad our freeways are. Get a picture of a speed xx (preferably the Speed 65 signs if they still exist by then.
I-205 between I-5 and Exit 6.
I will add that a trip to Voodoo Doughnuts is a necessity.
Someone on here mentioned that Voodoo was at best the 4th best donut shop in Portland. I agree... for locals. However, as a tourist, you should hit up Voodoo, if only so you can gripe about how overrated they are afterwards like us locals do.
Also, if the Chinese restaurant called Hung Far Lo still exists, try to get a picture of the sign.
I think the restaurant is closed but the sign still exists for now. It's on NW 4th & Couch (pronounced
cooch, by the way, not like the furniture).
Also to add: the OHSU aerial tram in Portland has great views of the skyline, I-5, and the mountains on a clear day.
Additional vantage points for awesome views are the International Rose Test Garden and Pittock Mansion, which are where a lot of east-facing photos are taken. There's also
this turnout off of Skyline Blvd. which, if memory serves, offers you great views of N Portland, Vancouver and (on clear days) Mt. St. Helens and Mt. Adams.
For cartography nerds, one place that's often overlooked is the Willamette Stone State Heritage Site, almost right across Skyline from that turnout. The Willamette Stone is the origin point for Oregon and Washington's land survey system. It's a brief forested walk along a paved path to the marker with a little plaque. There's usually no one there, so you may be able to get a little peace and quiet there as well.
In PDX I find one of the most scenic stretches being on 99E between Milwaukie and PDX. You go through a large corridor of trees on an expressway!
That is a beautiful drive. Terwilliger Blvd. between downtown and Barbur Blvd. is a pretty cool drive too. My favorite way to enter Portland (ignoring the traffic) is to take the Sunset inbound through the Vista Ridge Tunnel. You're essentially travelling through this thick green forested canyon, then after you go through the tunnel, BAM! there's the city. Just be sure to pick your lane before you get in the tunnel and stick with it.
Oh! Another non-driving attraction is Portland Saturday Market. It's basically a ton of local and regional vendors who set up shop near the Burnside Bridge over the weekend to sell their wares. It used to be
under the bridge, but the owners put up a parking lot (no pink hotel, boutique or swinging hot spot though) and forced them to move most of them to a spot at the north end of Waterfront Park. You might find something really cool and definitely unique there.