I believe Celtic Swell on Alki has Magner’s, which is pretty good, and Elliot Bay Brewery might have something on tap as well.
Nothing beats pints of Strongbow at Fremont’s George and Dragon. I don’t know if there’s any on tap out here, but you can get bottles of it at Metropolitan Market.
Elliot Bay does have cider on tap, nice and dry. They will let you try stuff before deciding on one as well. Black and Blue burgers and fish and chips go well with the beers too. mmmm