Snoqualmie Falls, Columbia Tower, Dim Sum for breakfast at Harbor City, Bainbridge Island Ferry, Museum of Flight, Kirkland Waterfront, Myrtle Edwards Park, Sea Plane Ride from Lake Union, Ballard Locks and Fish Ladder, Woodland Park Zoo, Seattle Aquarium, Pacific Science Center (if you have kids), taste some of the 200 wineries in Woodinville or the dozens of breweries in Sodo, Mariners game, Sounders game, Pinball Museum, Happy Hour at Palisade...I can probably think of more