I have relatives in the Gresham area of Portland, and friends in the San Fran area.
Portland: city of over a million people, but it's pretty easy to navigate. Homes range from about 240 to 300 K from the last five years of data, there's some very nice neighboorhoods, what lousy neighborhoods there were have really spiffed up according to my relatives, renting is about $675 for a studio up to $3250 for a 3 bedroom... I can suggest a few areas in specific in the Gresham area, if you'd like.
SF: Spendier. Cost of living's pretty dang high at 315 K minimum, on up to... well, 1.7 mil. That's San Fran for you. Renting is anywhere from about $900 (for less than 900 sq feet and 2 bed, 2 bath) to 4 grand plus. That being said, if you can afford it, it's an amazing place to live.
That being said, I have more experience with Portland, being an Oregon native. If money's tighter and you're looking for some place solid, Portland's the way to go.
