The Stranger is the best newspaper to find events going on.
Seattle CityPASS is a good value for the biggest Seattle sights.
⭐ Pike Place Market - Best spot downtown. Check out a guide to see any specific shops you might want to visit, but you can walk through the whole place in a few hours. Make sure to get there in the morning or around noon, since a lot of the stores and stalls close up pretty early in the day. Lots of good places to find food here. And there are a lot of interesting shops outside the market in the nearby streets. Check out Post Alley if you want to see the venerated Gum Wall.
⭐ Seattle Art Museum - If you only go to one art museum in Seattle it should be this one.
⭐ Seattle Public Library - It's a really cool building. You can go all the way to the top!
Westlake Park - Neat little park near all the fancy downtown stores.
Freeway Park - Neat abstract sculpture park near the Seattle Convention Center.
Sky View Obseravtory - Columbia Center - Observation deck in the tallest building in Seattle. Much better view than the Space Needle. A few years ago they renovated it and significantly increased the ticket price, however.
Definitely take a walk down the pier.
Seattle Aquarium Seattle Great Wheel - Worth looking at, but not worth the ride.
⭐ Seattle Center - The area around the Space needle. There's a cool park here that a lot of festivals are hosted at.
⭐ Chihuly Garden and Glass - Amazing collection of Chihuly glass sculptures.
⭐ Olympic Sculpture Park - Really neat outdoor sculpture park operated by the Seattle Art Museum. Free admission, and next to Myrtle Edwards Park, which has a beautiful view of the Sound.
Museum of Pop Culture - I haven't been here in a long time but it's a good museum. Even if you don't end up visiting, you should check out the building, designed by Frank Gehry.
Pacific Science Museum - Aimed more at young children, probably not worth visiting. Has a really good butterfly conservatory inside.
Space Needle - Expensive to go up, and not that great of a view. Worth standing under, if you want a good view of the city, go to the Columbia Center observation deck instead.
Ballard Locks - The locks where the fresh-water Lake Union meets the salt-water Pudget Sound. Peak salmon migration up the fish ladder from June to September, which is super cool to experience if you actually see any.
Museum of History and Industry - I haven't been here but it looks interesting. The Center for Wooden Boats - Cool naval museum.
"Quirky" neighborhood north of Downtown. Lots of interesting shops here.
⭐ Gas Works Park - Beautiful park bordering Lake Union, built around an old gas refinery.
Fremont Troll - Troll statue under the bridge
Lenin Statue - Near a lot of neat shops in Fremont. Also near a delicious Russian dumpling cafe.
Woodland Park Zoo
Fun neighborhood with lots of interesting shops, restaraunts, and bars. This is where I lived.
⭐ 8oz Burger & Co - Best burger in Seattle, and at the heart of Capitol Hill, a really fun place to walk around.
⭐ Tacos Chukis - Delicious tacos
The Elliott Bay Book Company - A neat bookstore
Bakery Nouveau - Delicious French bakery
⭐ Seattle Japanese Garden - Should be really pretty in the fall. Inside the Washington Park Arboretum, which is also worth walking around (it's HUGE).
Asian Art Museum - In Volunteer Park, which is a nice place to walk around, and sometimes has some festivals going on.
The Independent Pizzeria
There are some cool buildings at the University. I didn't explore too much around here myself though.
⭐ Din Tai Fung - Really good Taiwanese restaraunt. In University Villiage, a big outdoor mall in the U-District. If you eat here, make sure to get the dumplings. Henry Art Gallery
⭐ Il Corvo - PERMANENTLY CLOSED :( (Handmade pasta. Only open on weekdays for lunch, may have a 30-60 minute line, but IT'S WORTH IT.--this is the best restaraunt in all of Seattle. They have 3 daily rotating pasta dishes, and make sure to try the Focaccia).
Salumi - Really good deli
UPS Waterfall Garden Park - Tiny little park worth checking out if you're nearby.
Chinatown/Japantown
⭐ Uwaijamaya - Giant asian grocery store with some neat shops.
Danny Woo Community Garden - Neat little community garden you can walk around.
⭐ Harbor City Restaraunt - Probably the best sit-down Dim Sum restaraunt.
⭐ Dim Sum King - Tiny walk-in Dim Sum cafe, for a quick bite.
Oasis Tea Zone - Bubble tea shop. You should definitely get some bubble tea in the I-District, doesn't necessarily have to be here, but I like this place.
⭐ Living Computers Museum - Really cool computer museum with a lot of interactive stuff.
A bit out of the way.
Alki Beach - Closest beach near Seattle. Nice place to relax and maybe grab some food. Pronounced "owl-kai".
Bakery Nouveau - Owned and operated by the same people as the one in Capitol Hill. You should visit one of them.
Very out of the way, but might be worth checking out. Mega bougie and not a lot of things to do.
⭐ Hokkaido Ramen Santouka - Best ramen restaraunt in the Seattle area.
Downtown Park - Really neat park in the center of Bellevue
Bellevue Square - Giant mall with all your high-end shops.