Tully's coffee is pretty amazing. Seattle's Best Coffee is pretty good too. Starbucks is ok if you're in a hurry and need a coffee shop to go to. Convenience if anything. I had Seattle's Best yesterday and it was delicious and cheap.
You know I'm not sure I tried Seattle's Best... looks like I missed out! May be off to the States again next year in which I'm sure another visit to Seattle will be on the cards. I'll have to try it! (I'm all about the coffee!)