Fun things to do in Seattle (reachable via public transit from Capitol Hill)?

Hi! I’m going to have a few free days in Seattle: what are some cool things to do (both touristy and non-touristy)?

Ideally, they’d be accessible by simple public transit (e.g., not a complicated bus ride with three transfers), though I can also fetch a Zipcar for anything particularly exciting.

(I’m aware that someone asked a similar question in the past, but I’m looking for over the course of three weekdays, not just a few hours, so perhaps some different ideas will emerge.)

Thanks!