Let me put this out there; the only thing I know about coffee is how to spell it. However, this place treats coffee like a science. I love it.
It's in a weird space, seems like they carved out a hole in one of the tall buildings, but the ambiance is very cozy. They do this thing with the coffee where they slowly sift it through the filter with a lot of care. It's like dancing, which is another thing I don't know anything about.
They have a large selection of different coffees and teas and the baristas have a good idea of what you'd like if you give them some info about what you like. My barista was wearing a vest and bow tie, which, if you weren't aware, makes you awesome.
There's a lot of Starbucks around the city, but you definitely get a better experience at 21st Street.