Here is a quick list of places to eat outside the convention center.

Nearby the Convention Center:

Baguette Box
Good sandwiches and excellent fries. Slight walk uphill fast service.
1203 Pine St, Seattle, WA 98101

Tap House Grill
Local chain. Good food and a decent beer selection. 
1506 6th Ave, Seattle, WA 98101

Ruth Chris
High end steakhouse. 
727 Pine St, Seattle, WA 98101

Morton's Steakhouse
High end steakhouse.
1511 6th Avenue, Seattle, WA 98101

Blue C Sushi
Not my thing but ok reputation. 
1510 7th Ave, Seattle, WA 98101

RN 74
A little more upscale but the kitchen stays open a little later. Call to check. 
1433 4th Ave, Seattle, WA 98101

Further Away But Worth The Trip:

Dick's Drive In
A Seattle institution. Try the shakes. 
115 Broadway E, Seattle, WA 98102

Serious Pie
Good pizza but expect to wait for large parties. You can leave your phone number and they'll call when they're ready for you. Try the potato pizza. Seriously.
316 Virginia St, Seattle, WA 98121

Red Mill
Good Burgers. Different style from Dick's Drive In. Bring cash because they don't take credit cards. Try the onion rings.
1613 W Dravus St, Seattle, WA 98119