For me, it was the coffee shops, excellent sushi shops (e.g. Bamboo Sushi), the very wonderful Powell's Book Store, Finnigan's toy store, and the many friendly people we found. It was a city where the air is fresh and the energy of living permeates the community. In Japan, such cities are many but in the U.S. I can think of only a few where the pulse of life is felt as you walk the streets.
The coffee shop below had excellent brew; but, it was the visuals that I enjoyed the most. Situated in an old building with a good street view and 'the regulars' walking in and out. I looked around at the clientele and was reminded of Austin in the mid 1970's. By appearance, these where people in touch with who they were and who understood the philosophies they carried about in their heads.
There is a lot to do and see in Portland, but like few other cities it is just a wonderful place to be.