Gwendolyn Richards is a food writer for the Herald and one of my culinary sherpas. Here is her blog post on Portland
http://www.patentandthepantry.com/20...-eat-a-burger/
The burger at Gruner was sublime.
Also, hit food trucks. They have a couple of parking lots downtown surrounded by them semi-permanently.
If you like coffee, there are myriad options - Heart being my favorite. Also - Stumptown (natch) and Public Domain roasters.
And finally, it's the pacific northwest so the beer options are almost overwhelming. So much good stuff down there. I'll see if I can remember a few later and post a follow up.