Ex Portlander here!!!
it really depends on what your interested in...Portland has a variety of great restaurants both casual and fine dining, some pretty decent museums, amazing scenery, lots of bars, clubs and little smoky pubs, and IMO some great shopping as well...(I LOVE THE OLD PORT)
It's quite similiar to Boston, only on a much smaller scale
But I'm guessing your wanting specifics

,so let me know are you wanting some great sushi? great seafood in general? a good sandwich? Are you more into clubs/pubs? or historical places/museums?...I can recommend some specific places once I know more about your tastes.