We had a group of us who went to Alaska via Seattle last September.
Between all of us, we stayed at The Maxwell, The Warwick, Comfort Suites @ Tukwila(out near the airport), and The Red Lion.
None of us had any complaints. We all liked our individual hotels, it just depended on where you wanted to stay and how much you wanted to spend.
Check Trip Advisor for reviews, recommendations and prices.
Have a great time!