Two go-to's! Both loops have nice water views and 700 to 1,100 feet of gain.
An about 15 mile loop from home to Golden Gardens Park on Puget Sound with variations on the way home.
23 mile loop along the Ship Canal, through Discovery Park, along Magnolia Bluff (really, Capt Vancouver did not know Madrone trees back then) and then through Myrtle Edwards Park, and home via Seattle Center and the Space Needle.