The sounder, the 1-line, the ferries. Seattle is pretty great for public transportation. The only place I’ve seen better is Vancouver, but I’m not super well traveled.
But if coming from Tacoma to go watch college hockey in Northgate? There’s no better way to travel than the 1-line, IMO. Or trying to get to the airport without all the insane traffic and poorly designed on and odds? 1-line.