Bars that serve dark beer

I think some of you can help me out here-
with spring here and my intensive language course behind me, I feel the need to drink more!
I like the German beer okay, but what I really miss is my local brewery back in the states! They had really great brews, modeled after Belgian beer- dark, malty, complex and strong!
Anyone know of a bar to recommend that offers other dark beers besides the Guiness/Harp Irish brews? (that seems to be the darkest I can get in my area of Berlin).
What I'd love to find is a bar that has selections from all over the world.
any recommendations? Many thanks!

Checkout Mommseneck Am Potsdamer Platz (Alte Potsdamer Str. 1 - near the Ritz Carlton) for a selection of more than 100 international beers or the Haus der 100 Bier on Mommsenstrasse 45 in Charlottenburg, off Kurfurstendamm

Try Köstritzer Schwarzbier -- it's a dark lager and you'll find it, in bottles at least, in most pubs and restaurants. Absolutely delicious. I can't believe that you won't be able to find a Kneipe serving it near you. (Other ones to look out for are Erdinger Dunkel (a dark wheat beer) and Flensburger Dunkel.)

Most of the brewpubs, Eschenbräu (Wedding), Bräuhaus Spandau, Markusbräu (Mitte), to name a few, have a dark beer on their list.

Or try Aufsturz in Mitte. A large selection of bottled beer.