Fremont for the cafes and feel. Lenin and the troll...Waiting for the Interurban...Burke-Gilman trail hookup there too. So, a possible bike ride? I think the other PNWers could guide you better on the BGT.

Snowshoing's not my cup of tea, but there's not really anything THAT close to Seattle itself (everyone feel free to correct me if I'm wrong). Closest I can think of would be Mt. Baker, but that's possibly a little more out of your way than you may wish.

East Hill