Can't beat the location
We frequently fly out of Seattle coming down from Canada (Vancouver area) by car. For a great room, regular shuttle, parking included in room rate for 7 or 10 days, the Doubletree is hard to beat. Short trip to and from Airport, friendly staff (sometimes a bit overwhelmed because it is always busy), food onsite but lots of good choices within walking distance (Sharp's Roaster, Mango Thai, for dinner, Dave's Diner for breakfast) and of course the nice chocolate cookie on check-in.