I first experienced Blue Bottle when I was in Brooklyn with Raw Nerve for a show back in October 2010. A friend took a few of us there when she heard how into coffee we were. It's on Berry and 3rd (I think) and has a big glass front, pretty snazzy innit. Inside it is very minimalist and kinda like a space ship (if space ships had an espresso bar... in my dreams they do and are flown by cats).
The shop is also a roastery, supplying beans directly to the coffee bar. And I mean directly - they probably walk like 10 feet and pass it to the barista. NOW THAT'S FRESHNESS YOU CAN'T BEAT. It's pretty cool to watch the roastery at work, you don't often get to see 'behind the scenes' and all the machinery is the real deal top notch fancy ass bullshit.
Unsurprisingly, the coffee is excellent. I went a few times as visiting Williamsburg is awful unless you can make your trip worthwhile in some way. Latte - great. Cold brew - GREAT. So great. Would drink forever and die of a heart attack as it's really strong.
The company is actually based out in Oakland and has shops there as well as San Francisco.
BB is definitely worth a trip, not for the coffee alone but the aesthetic experience of seeing the beans being roasted and ground as well as watching your drink being prepared - the V60s are all lined up by the cash register so you can observe the unique brewing process. Do it, brave Bedford Ave, it may be torture but it's character building (right?)