The Sheraton Seattle and the W Seattle are sold out.   Here are some nearby  hotels that may have availability: 
Hotel Vintage Park, 1100  Fifth Avenue, Reservations:  800-853-3914
Crowne Plaza Hotel, 1113 Sixth Avenue, Reservations:  800-521-2762
The Fairmont Olympic Hotel, 411 University Street, Reservations:  800-257-7544
Hilton Seattle, 1301 Sixth Avenue, Reservations: 206-624-0500