Yarn Garden is most likely the biggest yarn shop in Portland, and the one that is most likely to be open when you decide you need a new project during the Simpsons. They have a room of patterns and books and magazines, and some comfortable seating in the coffee shop. They stock lots, if not all, of Noro and Brown Sheep (including a healthy selection of Lamb's Pride worsted and bulky, and Burley Spun), needles by Lantern Moon, Addi, Daisy, Clover, and Bryspun, lots of knitting bags, baskets and purses, and tons of sock yarn including the self-patterners, wildfoote, and koigu. And if you just look at the pretty displays, you'll think that everything here is really expensive. If you're looking for acrylic or baby yarn or cheapies, ask.
And there in lies the problem. Yarn Garden can be claustrophobic in the best of circumstances, and the staff seem overextended and somewhat clueless. It's fine if you know what you need, can figure out how to find it on your own, and if you don't mind a crowded store. But, if you're claustrophobic, or need handholding, this is not the place for you.