Any memorable places in Seattle for a tourist?

Check out the Volunteer Park water tower for the best (and free) views of the city. 

Red Square has incredible views of Mt. Rainier, and the Suzzalo library reading room is spectacular. 

If you're into computers, then I would also recommend checking out the Living Computer Museum

I guess that depends on what you find to be fun. I can't imagine being here all summer and not doing anything fun yet. I won't mention the better known touristy places as you probably already know of them. I tend to enjoy outdoor activities and scenery the best, so here are my thoughts...
Explore Discovery Park from the top all the way to the beach. Low tide is a fun time to go down there. You've probably heard of Alki Beachbut it's pretty fun to rent a bike and ride along the path parallel to the water. You can make it more novel by taking a water taxi from the city and visiting some delicious food trucks that hang around there. Maybe try visiting the neighboring islands, like quiet Vashon (Washington) or Bainbridge Island? Or go farther afield to the San Juan Islands or the Penninsula for hiking, biking, camping, or whale watching. Back to the city... everyone goes to the top of the Space Needle, but there are some great views from the top of the Columbia Center and Smith Tower too. Food places I would recommend are Qazis Indian Curry House and Mediterranean Cuisine and Paseo Caribbean Restaurant in Fremont, Pam’s Kitchen in Wallingford, Hot Cakes Molten Chocolate Cakery in Ballard, and pretty much any waterfront seafood restaurant in the city. If you haven't had seafood here, it's a must! Just go walking around the small urban neighborhoods like Fremont Neighborhood and Ballard Neighborhood and you'll find plenty of quirky, memorable things to do and see. There are a million things to do in and near this city!

Try hiking if you enjoy the outdoors and are remotely athletic. wta.org has ratings and info on hikes. I fell in love with hiking my first summer here. Wonderful waterfall hikes and mountain views! Also, find a way to go on a boat. The Electric Boat company can be a good option with friends, you can bring booze and food on board and go where you want to go within South Lake Union and part of the canal.

Since you've been here all summer you've visited Pike Place Market, right? Definitely a must when in Seattle. Spend some time at Kerry Park (best view of the city in my opinion) and eat at The Walrus and the Carpenter! 

Start your morning at Kerry Park. Either run up Queen Anne or ? Alternately watch the sun set , if you lucky. The locks are good for fish, hamburgers at red mill and then head to Zebraclub to shop for that rain jacket and danner shoes before you trip over to seattle art followed by Wing Lok and cap of with dinner at the Wild Ginger