D.C has quite a few beer gardens to choose from and they each have their own vibe. Garden District on 14th street has a more relaxed feel along with awesome donuts. Dacha is a great place to bring your dog and sip on a beer or six. However, if you want a rowdy beer garden/beer hall look no further than Sauf Haus in Dupont Circle on a Saturday.
Sauf Haus has two floors of Bavarian awesomeness plus a beer garden on the roof. They have a variety of German beers along with the proper glasses that they are meant to be enjoyed in. There are usually about 16 beers on draft, but there are also “beertails” and seasonal beers on rotation. The bartenders are quite knowledgeable about the selections so if you know generally what flavors you like in your beer, they can help you out.
My favorite part though is the seating. There are communal tables so you end up meeting new people and having great conversations over a giant 2 pound pretzel and stein of beer. Sauf Haus does get very packed so if I were you, I would get there right when they open and just post up in one spot. Otherwise, you are going to be stuck standing scanning the room for an open table for hours. Prosit!