My SO and I will be visiting Portland and Eugene, each for one day/night. I'd like to go for meals at restaurants that have regulars as customers. Let me give an example - here in the Phoenix area, my SO and I are well-known at our favorite restaurant, Carlsbad Tavern. We go there at least twice each month, and it's our default comfortable relaxing evening with great food.
No cuisine is off-limits. We are equally happy eating sushi, hummus, burgers, burritos, etc... Affordability is a plus, and a casual vibe is necessary.