Awesome Jewelry by Joellen A. at InsiderPages
This place is a bit more spendy than your average jewelry store but well worth the service you get. You can consider yourself a regular after one purchase! They are friendly, always offering discounts and willing to work a deal to get you what you want. They are the only jewelry shop I look at now.
Read more at portland.citysearch.com
PROS: Friendly, wide selection, high quality, will offer special discounts.
CONS: More expensive than most others.