Intelligentsia has the best coffee in the city - I am not a huge espresso fan as I don't think there is much difference in flavor between the various chains. However, as far as regular coffees go, Intelligentsia has the most flavorful and broadest selection I have ever seen. YUM!!
BTW - expect to wait a little for regular coffee because of the fact they make it with 'clover' machines - these are $12,000 machines that simulate a french press but get the coffee made in something less than a minute. I'll take totally fresh coffee and wait a little for it rather than drip coffee that has been...