Three Girls Bakery! They're in a temporary spot downstairs from the Crepe place. Ask around... they're worth finding. They've been in Pike Place since 1912 had have the BEST salmon sandwich (and the egg salad ain't half bad either)!
Also, check out Beecher's Cheese on the corner of Pine across the street from the market. They make their cheese on-site, and their Mac & Cheese is absolutely delicious!
If you're looking for a treat afterward, I highly recommend The Confectional (on the other side of Pine heading South from Beecher's). They make tons of flavors of single-serving cheesecakes, and also have mini-bites. Caramel is my favorite, but they're all amazing.