We have stayed five times at the Quality Inn Sea Tac for our HAL cruises to Alaska.  They pick you up at the airport and shuttle you to the cruiseport.  Also, a breakfast was included.  It isn't the fanciest hotel, but it was clean and the service was great.  So helpful in giving us tips to see things before/after the cruise.  It has been a few years since we stayed here, so hopefully it hasn't changed.  Check it out.
Quality Inn Sea Tac
2900 South 192nd Street
SeaTac, Washington 98188
Phone: 206-241-9292
ewmail: gm.wa153@choicehotels