At the Seattle Waterfront, you can visit Pike Place Market, Seattle Aquarium, Gum Wall, Sculpture Park as well as tons of bars, cafes, and restaurants. The city has recently invested over $800 million reinventing this area and is a very cool sight to behold on a nice day.
Take the Water Taxi to West Seattle (10-15 minutes water taxi) then a short free shuttle to the main strip. This area sits on a beach with views of the Pugent Sound, distant islands and the Olympic Peninsula. There are several bars and eateries available to take it all in.
This is the spot to check out the Seattle skyline where most photos of Seattle in the media are taken at. After that, go to the top of Queen Anne and enjoy a lunch or dinner.