Commonwealth is a homey Park Slope bar that bills itself as "indie," yet somehow neutralizes pretension as soon as you walk in the door. This is a very good thing.
I can't speak much for the beer selection (although I hear they serve a great Dark and Stormy), so I will instead review that somethingsomething known as "atmosphere": it's excellent here, enough to make you wish this was your local. Three points make it so. First, a fantastical jukebox: Sebadoh, the Zombies, Smashing Pumpkins, Andrew Bird (<3), Radiohead, Mum. There is even a small stool reserved for song-selection, so you can recline in comfort while you choose your tunes (25-cents each!). Second, an anonymous personals board, so you can tell other Slopers what you're looking for in a partner after you're tipsy enough to admit it to yourself. ("Guy seeks girl who likes cookies.") Last, a charming patio area. Shame it'll be thirty thousand degrees below zero before long, but file away for next springtime and you won't be sorry.
Oh, and the concert poster art on the walls is cool. I think they also have a digital clock with a picture of Mao ze Dung on it.
Commonwealth, 497 5th Ave between 11th and 12th Sts