Thanks for this post I'll be visiting the baltimore area for Christmas time flying in to BWI from Germany. Need to pick up some nice American craft beer!
I usually end up going to Corridor first, then to Perfect Pour for everything I couldn't find at Corridor.
Also good is Stateline Liquors right off 95 just before crossing into DE - they have a craft brew discount too if you sign up with them (which is free).
I'm glad someone mentioned Stateline. Incredible beer selection, club card discounts, great tastings, great staff. If you find yourself in that area, this is a must stop...seriously!
The best liquor store depends on your interest. For wine, Wine Cellars of Annapolis with their barrel open and free tastings cannot be beat. But for beer selection, I also usually go to Corridor. However, Corridor while they have a broad selection of wine does a terrible job with tastings and recommendations.