According to Imbibe Magazine (#15), Baltimore has 2 of the best places to drink beer in America! (and it's a big place!).
The Brewer's Art
Heaven on the main floor, Dungeon in the basement.
#2 I'm sorry to say, I have never been here:
I guess that's why it's in the "Best Kept Secrets" category!
Thanks Atomic for the heads up!