I have stayed in the Marriott Courtyard in Tukwila for business and
found it was easy to get to the museum and there is a mall acroos the
street to give the family something to occupy themselves while you are
having fun.
There is a good place nearby called Claim Jumpers that isn't too bad
either. Just go hungry.
http://www.claimjumper.com/
The Motherlode chocolate cake is huge and you almost need a ladder to
climb up to the top to eat it.
Tom