This list is not complete.
Space Needle (Competed Jan 4, 2014)
Aquarium (Completed Dec 28, 2013)
Pike Market (Completed Aug 2014)
Woodland Park Zoo (Completed July 2015)
Watch Salmon run (Completed April 2014)
Go Whale Watching
Discovery Park (Completed Feb 22, 2014)
Gas Works Park (Completed July 2015)
EMP (Completed September 2015)
Botanical Gardens (there are two. One is in Seattle and one is in Bellevue)
Seattle Art Museum
Science Center (Completed June 2015)
Olympic Art Garden
Native American museum
Asian Art Museum
Pioneer Square gallery
A show at one of the early venues Nirvana played at
Kurt Cobain pilgrimage
Visit Jimi Hendrix's grave
Visit the first Starbucks. ( Completed July 2014)
Major sporting event
Wander around Fremont and find: the troll, Lenin, the rocket, and other street art.
Visit Mt. Rainer, the Olympic Mountains, and the North Cascades. (not in the same trip though).
There are some things I'd like to add: like find the good restaurant, the main road race for the city and participate, and some of the other pop culture stuff, find a really awesome coffee place, and shop the more interesting boutiques. These ones are more nebulous but when I figure out what the are I'd like to do them.