Though Seattle has plenty of terrific local gourmet shops some of which are listed below you voted national chain Trader Joe's your favorite place to pick up gourmet fixings, and that's fine; Trader Joe's food and beverages go well on any table. Still, we doubt Trader Joe's would mind if you mixed its groceries with some Northwest ingredients purchased from other local gourmet shops.
You also mentioned...
World Spice Merchants, the Queen Anne Thriftway, Red Ribbon Gourmet, Le Gourmand and "farmer's markets."