If you happen to go to the Seattle Trade Center, get on the monorail and it'll take you to the Seattle shopping district where there are HUGE Flagship stores of Nordstroms, The Bon, Old Navy, Gap, Abercrombie and Fitch, and so on and so forth. It was great fun, and unexpected.
A good way to save a few bucks if you're planning to see a lot of stuff is to get a City Pass. It included the zoo, space needle, aquarium, art museum and a couple other things that we didn't make it to and I don't recall now. It was $25/person back in 98.
Take the monorail from the center of town to the Space needle. It cost $1 when we were there. It was built for a World's Fair, I think, many years ago. It only goes about 1 mile, but is a fun little ride.
If you can make your way to the grave site of Bruce Lee (I took a nice bus ride) you can view the site of a martial arts legend, have a walk in peaceful surroundings, and get magnificent views of the rivers surrounding the city of Seattle.
Go and look down on Seattle from the observation room in the Columbia Centre Building. This is at 5Av and Columbia Street. It's a normal office building but you can go up to the obersvation deck. It is open during normal office hours and costs about $5.
The Northwest Folklife Festival is every year on Memorial Day weekend, all across Seattle Center. Tons of interesting things to see and do, and bst of all is the nonstop, super-ecclectic live music.
There are dozens of food booths from many different cultures -- try something you've never eaten before!
The picture is from what's generally called 'Drummer's Cove' -- an unofficial gathering of drums and dancing of all kinds. It's an exciting atmosphere, but without exception strong smelling from smoke of several types.
Lots more information on the website:
When you are ready for lunch after strolling through the town, try the Ludwig restaurant. Try the famous pork roasted entree serve with sauercrauts and an ice cold glass of beer. It is a big meal and big enough for two.
Queen Anne Hill, which overlooks , the downtown part of Seattle. An area which is on a neighborhood, that has it's own park, which a great landscape view of Seattle and it's waterfront.
Seattle has a very nice zoo, I think it's called Woodland. I could watch otters and monkeys for a very long time, they crack me up!